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Recomended mobo for HD6990 in Crossfire.

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  • Crossfire
  • Motherboards
  • Graphics
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July 27, 2011 7:41:09 PM

Hi

I was just after some recommendations for motherboards to take 2 HD6990 in crossfire. I didn't want to spend hundreds but I'm unsure what would be the best for the job.

My spec is i7 2600K, Asus P8H67-M, HD6990, XFX PRO750W PSU. 12GB DDR3 RAM.

I have 1 graphic card for now but would like to get another in the future so would like to upgrade my mobo for something i can use when i do. Also something that would allow better overclocking of the CPU would be good. I don't think my current PSU will cope with 2 graphic cards but would like advice on that as well if anyone can help.

Thanks

More about : recomended mobo hd6990 crossfire

July 27, 2011 8:03:41 PM

davexxsmith said:
Hi

I was just after some recommendations for motherboards to take 2 HD6990 in crossfire. I didn't want to spend hundreds but I'm unsure what would be the best for the job.

My spec is i7 2600K, Asus P8H67-M, HD6990, XFX PRO750W PSU. 12GB DDR3 RAM.

I have 1 graphic card for now but would like to get another in the future so would like to upgrade my mobo for something i can use when i do. Also something that would allow better overclocking of the CPU would be good. I don't think my current PSU will cope with 2 graphic cards but would like advice on that as well if anyone can help.

Thanks

I hate to be the bearer of bad news. but the driver support for this is simply trash. Some games won't even load up (i.e. aliens vs predators) and other games won't register the second card and will net the same results as 1 card (i.e. lost planet 2)

if you wanted I would suggest crossfire 2x 6970's or 2x 580's

however to answer you: Any z58 mobo with room for 4x pci-e slots as each card takes up 2 in regards to space, otherwise your losing overclocking capabilities... lol not that you'll need them with that rig

edit: A new Catalyst came out today. Perhaps this will be your saving grace..? doubt it though.
July 27, 2011 8:35:18 PM

Hi

i agree that the ATI drivers are not as good as the Nvidia, we have had driver probs with many games running eye infinity and ended up back on 1 monitor.

I already have one 6990 so will hope the driver issues sort out when i do get another. I did post about its dissapointing performance a while ago. I still wonder if its running as it should as it docent hardly make any noise except when the pc first comes on. I did get decent benchmark scores after advice on the previous thread. I have no idea why the fan dosent seen to ramp up even when its being used for gaming.

i still think ill need another psu if i ever buy another card.

dave

Related resources
a b V Motherboard
July 27, 2011 8:45:39 PM

For two monster 6990's you need NF200 chipset motherboard
ASUS P8P67 WS REVOLUTION
get yourself a corsair HX1000 or AX1200
July 27, 2011 9:26:19 PM

is this mobo ok,
Asus P8P67 Deluxe Version 3 Socket LGA1155 Motherboard
im not to sure about the pcie slots, x16 and x8. Do i need it to have 2 x 16
a b V Motherboard
July 27, 2011 10:26:51 PM

redeemer said:
For two monster 6990's you need NF200 chipset motherboard
ASUS P8P67 WS REVOLUTION
get yourself a corsair HX1000 or AX1200

And how will an Nvidia chipset help?
July 27, 2011 10:40:02 PM

Mousemonkey said:
And how will an Nvidia chipset help?



sorry, i dont know what you mean?
July 28, 2011 12:46:05 AM

I would advise saving some cash and purchasing a 6970 instead. I run tri-fire 6990 + 6970 and had thought of quad-fire 2*6990 but the performance increase is not worth the cost.

In terms of motherboards it depends on you budget. Ideally you want x16/x16 capability which gives you the choice of the following with a NF200 chipset:
1. ASUS Maximus IV Extreme Z, $465AUS http://www.pccasegear.com/index.php?main_page=product_i...
2. ASUS P8P67 WS Revolution, $359AUS http://www.pccasegear.com/index.php?main_page=product_i...
3. Gigabyte GA-Z68X-UD7-B3, $365AUS http://www.pccasegear.com/index.php?main_page=product_i...

Of which I would recommend either the MIVE or the UD7, it really comes down to your preference and if you fancy the ROG extras on the MIVE.

The difference however between x16/x16 and x8/x8 is roughly 1% so if you want bang for your buck get a ASRock Extreme 4 Z68 for $209AUS like I did.

Also invest in a Corsair AX1200, you wont regret it and depending on what peripherals you run you may need it, the 6990's are very hungry at full load. If your overclocking I cant advise this PSU more strongly.

What resolution do you run, if you are running eyefinity I advise the set up i've mentioned above (6990 + 6970 destroys 580 SLI and is cheaper) if your running a single monitor will the additional graphics card really give you any noticeable performance improvement?
a b V Motherboard
July 28, 2011 7:19:06 AM

davexxsmith said:
sorry, i dont know what you mean?

Whilst an NF200 chipset will give you dual x16 PCIe for SLi will it also allow dual x16 for Crossfire?
July 28, 2011 11:36:07 AM

Ninja Pants said:
I would advise saving some cash and purchasing a 6970 instead. I run tri-fire 6990 + 6970 and had thought of quad-fire 2*6990 but the performance increase is not worth the cost.

In terms of motherboards it depends on you budget. Ideally you want x16/x16 capability which gives you the choice of the following with a NF200 chipset:
1. ASUS Maximus IV Extreme Z, $465AUS http://www.pccasegear.com/index.php?main_page=product_i...
2. ASUS P8P67 WS Revolution, $359AUS http://www.pccasegear.com/index.php?main_page=product_i...
3. Gigabyte GA-Z68X-UD7-B3, $365AUS http://www.pccasegear.com/index.php?main_page=product_i...

Of which I would recommend either the MIVE or the UD7, it really comes down to your preference and if you fancy the ROG extras on the MIVE.

The difference however between x16/x16 and x8/x8 is roughly 1% so if you want bang for your buck get a ASRock Extreme 4 Z68 for $209AUS like I did.

Also invest in a Corsair AX1200, you wont regret it and depending on what peripherals you run you may need it, the 6990's are very hungry at full load. If your overclocking I cant advise this PSU more strongly.

What resolution do you run, if you are running eyefinity I advise the set up i've mentioned above (6990 + 6970 destroys 580 SLI and is cheaper) if your running a single monitor will the additional graphics card really give you any noticeable performance improvement?



hi

If i tri fire 6990 and 6970 does this reduce the performance based on the lower card, suppose not as that's what you are running.
I was running 3 x24" monitors in eyeinfinity at 1940x1080 res, cant remember the exact numbers, think that's what it was. Its really my sons setup, im just the wiring up and buying part really.

The eyeinfinity looked amazing but the FPS on most games seemed worse than when we use to run single monitor using our old 4870x2 or the 460gtx we have also.

As you run the 6990 is yours noisy, we never hear ours and this continues to surprise me, if i check the graphs for afterburner both GPU's run around the 75% and the temp i think is in the 70's as well. The fan is only noisy when i first start up the pc.

If i tri fire do i need the 6970 or do i get a 6950 and unlock it.

thanks dave.
July 28, 2011 12:33:19 PM

davexxsmith said:
hi

If i tri fire 6990 and 6970 does this reduce the performance based on the lower card, suppose not as that's what you are running.
I was running 3 x24" monitors in eyeinfinity at 1940x1080 res, cant remember the exact numbers, think that's what it was. Its really my sons setup, im just the wiring up and buying part really.

The eyeinfinity looked amazing but the FPS on most games seemed worse than when we use to run single monitor using our old 4870x2 or the 460gtx we have also.

As you run the 6990 is yours noisy, we never hear ours and this continues to surprise me, if i check the graphs for afterburner both GPU's run around the 75% and the temp i think is in the 70's as well. The fan is only noisy when i first start up the pc.

If i tri fire do i need the 6970 or do i get a 6950 and unlock it.

thanks dave.

I believe most of the new cards aren't able to be unlocked (6950's) they caught on rather rapidly. If you do crossfire a 6970 and a 6950, just be sure to set 6970 as your primary.

Doing these in crossfire x 3 is a great option. I would suggest a good ol' gigabyte mobo

http://www.pccasegear.com/index.php?main_page=product_i...
July 28, 2011 12:44:17 PM

jonnyrb said:
I believe most of the new cards aren't able to be unlocked (6950's) they caught on rather rapidly. If you do crossfire a 6970 and a 6950, just be sure to set 6970 as your primary.

Doing these in crossfire x 3 is a great option. I would suggest a good ol' gigabyte mobo

http://www.pccasegear.com/index.php?main_page=product_i...



Hi jonnyrb

i was planning to follow ninja pants recommendation, i have a 6990 and was thinking about another to get good eyeinfinity performance but he suggested. My 6990 and a 6970 in tri fire. I believe the 6990 would have to be set as the primary, is that correct. Its an endless money pit isnt it, from another expensive 6990 i now need a new PSU (£225) a new mobo (anything up to £250) then the card. I might go with the mobo he recomended, running at x8 at a1% loss. Im not planning on the purchase for a few weeks so anything can change by then. Never know i might win the lottery, id prob spend most of it on PC stuff and still want more.

:-)
July 28, 2011 12:59:24 PM

davexxsmith said:
Hi jonnyrb

i was planning to follow ninja pants recommendation, i have a 6990 and was thinking about another to get good eyeinfinity performance but he suggested. My 6990 and a 6970 in tri fire. I believe the 6990 would have to be set as the primary, is that correct. Its an endless money pit isnt it, from another expensive 6990 i now need a new PSU (£225) a new mobo (anything up to £250) then the card. I might go with the mobo he recomended, running at x8 at a1% loss. Im not planning on the purchase for a few weeks so anything can change by then. Never know i might win the lottery, id prob spend most of it on PC stuff and still want more.

:-)


If you do tri fire with a 6970 the x8 will sort of suffice. if you DO end up getting 2x 6990's you'll want x16
July 28, 2011 1:11:33 PM

Hi

Ill check whats available, i would like the x16 board just in case and will prob save money in the long term. Id hate to be back again wondering what to upgrade to in 6months or so.

thanks
July 28, 2011 1:23:42 PM

Quote:
If i tri fire 6990 and 6970 does this reduce the performance based on the lower card, suppose not as that's what you are running.
I was running 3 x24" monitors in eyeinfinity at 1940x1080 res, cant remember the exact numbers, think that's what it was. Its really my sons setup, im just the wiring up and buying part really.

You should have your 6990 as your primary card, as it is basically 2 6970's and maintains the 2GB VRAM the only performance loss you will sustain is if the 6990 is not in the AUSUM mode and the core clock is underclocked to 830MHz, this will cause the 6970 to operate at 830MHz. Note that AUSUM mode is only covered in the waranty for Powercolor and XFX branded 6990's.

Quote:
As you run the 6990 is yours noisy, we never hear ours and this continues to surprise me, if i check the graphs for afterburner both GPU's run around the 75% and the temp i think is in the 70's as well. The fan is only noisy when i first start up the pc.

It is a noisy card, it doesnt worry me in the slightest, even at full load I don't think its too bad. What you hear on startup is the worst it will get (at least it has been for myself).

Quote:
If i tri fire do i need the 6970 or do i get a 6950 and unlock it.

If you can find a 6950 that can still be unlocked, then yes save some cash, but the new ones do not allow you to do so so buy carefully.

Quote:
Whilst an NF200 chipset will give you dual x16 PCIe for SLi will it also allow dual x16 for Crossfire?

Sure will.


Let us know if you need any further help Dave I just finished a very similar build and sorry for the late response clearly on different time zones.
July 28, 2011 4:34:42 PM

thanks everyone.

Ill let you all know when i get it sorted.

Im planning ebaying some stuff to firstly upgrade the mobo, if i can to a x16 x2 type hopefully this mobo will allow me to OC the sandy bridge that i have running at the 3.4ghz, prob a bit of a waste. My current mobo will auto OC it by 15% but then im a bit stuck.

If that all goes ok ill plan the PSU upgrade and then the HD6970 is the plan in tri fire.

Then ill get my 3 monitors connected back up in eye infinity.

If im still disappointed then i think ill just brush the dusk off the PS3 and xbox.

cheers all.
July 29, 2011 5:07:31 AM

Any of the Mobo's with the NF200 controller listed above (possibly with the exception of the WS Revolution, never used it and not seen a benchmarking revue using it but one would assume it would overclock well) will overclock brilliantly.

The ASRock I recommended above also overclocks well, with decent cooling there is no reason your sandy bridge shouldn't be able to do 4.5GHz+. Dont be fooled by the UD7's 24 phase power, 8 does just fine, you dont need an enormously expensive board to achieve some good numbers with a Sandy Bridge.
July 29, 2011 10:12:35 AM

Ninja Pants said:
Any of the Mobo's with the NF200 controller listed above (possibly with the exception of the WS Revolution, never used it and not seen a benchmarking revue using it but one would assume it would overclock well) will overclock brilliantly.

The ASRock I recommended above also overclocks well, with decent cooling there is no reason your sandy bridge shouldn't be able to do 4.5GHz+. Dont be fooled by the UD7's 24 phase power, 8 does just fine, you dont need an enormously expensive board to achieve some good numbers with a Sandy Bridge.



hi

The price of the ASRock Extreme 4 Z68 is £142 on e buyer and at that price i would be happy to buy it now. Its still only x8 if 2 PCIe slots are populated ( i may be missing something). You did say id loose about 1% performance but for the cost i dont think its bad. If i do this upgrade i don't think ill then want to go for the 2 X HD6990 cards in the future. It does look like theres enough room for the 2 GPU cards to fit on the board. There are some on ebay at the moment with low bids im watching.

I still feel the HD6990 doesn't perform as i expected, maybe its my CPU holding back the performance, that's why i also wanted a board that could overclock the cpu easily. I have a H50 water cooler on the CPU so cooling shouldn't be a problem. I think it idles @ 30 deg and runs normal loading around 40. Id check before tinkering.

July 30, 2011 12:44:41 AM

Yes the ASRock is only x8/x8 if two PCIe slots are populated (x8/x8/x4 if 3 from memory), but as I said the performance difference compared to x16/x16 is tiny. There is room for three GPU's if you so wish but the good thing about the ASRock when running 2 cards is that there is a nice one slot gap between them allowing for proper air flow, this is very handy when running a 6990 particularly as the fan is on the underside of the card.

Your CPU could potentially be the bottleneck but really your Sandy Bridge shouldn't be an issue, it would also depend on what programs / games you are running as some are obviously GPU heavy (GTA IV for example) and others are CPU heavy. There are allot of variables and you would have to do do some tests to determine if it was your CPU that was the bottleneck. In terms of CPU temps (I assume you do this as part of your OCing) running Prime95 and checking the Max/Avg Temps through something like coretemp or realtemp will give you a better idea your cooling / OCing capacity.
July 30, 2011 4:28:40 PM

Hi

Im going to try and get the Asrock you recommended. I was monitoring the CPU temps when i did the 1 button OC thing, that increased by 15% performance. I ran prime95 and everything was fine.

thanks, ill try letting you know ho it goes when i get it. Will have to wait a while for the PSU and the other GPU.

August 31, 2011 3:02:40 AM

I'm trying to accomplish the same thing... My build consists of the following:

Corsairs 800D
Corsairs AX1200
I7 2600K OC to 5.0
ASUS Maximus IV Extreme-Z
G.SKILL Ripjaws X Series 16GB (4 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)
x2 OCZ Vertex 3 SSD (RAID 0)
x4 1TB Western Digital Black's (RAID 10)
Blu Ray combo drive
Sapphire Radeon HD6990 4GB AT-HD6990
Sapphire Radeon HD 6970 2GB 100311SR
3x Samsung PX2370 23-Inch Widescreen LCD Monitor with LED Backlight


So, with all that said... How am I doing? Will I be able to successfully trifire my system?

P.S. how did you build turn out?
August 31, 2011 5:02:06 AM

Seriously nice build. Only thing I would say is consider a XFX or Powercolor 6990 as they offer an extended warranty including the use of ASUM mode (performance increase of around 7% on the 6990 but will also allow the 6970 to run at 880MHz so overall increase of ~10%).

I would question your storage options but given you are looking at the top echelon of components I will assume you have a good reason for it.

You've left out CPU cooler and RAID controller for your SSD's (if you plan on it)
August 31, 2011 2:11:05 PM

Ninja Pants said:
Seriously nice build. Only thing I would say is consider a XFX or Powercolor 6990 as they offer an extended warranty including the use of ASUM mode (performance increase of around 7% on the 6990 but will also allow the 6970 to run at 880MHz so overall increase of ~10%).

I would question your storage options but given you are looking at the top echelon of components I will assume you have a good reason for it.

You've left out CPU cooler and RAID controller for your SSD's (if you plan on it)



I have already purchased my components and the awaiting the cards via mail... So, it's a bit late to change up now without an RMA. As for my storage I'm assuming you talking about the RAID10 setup. Yes I did this for a reason, but not a good one... :)  I wanted the dual parity and maintain the performance of RAID 5. So, I took the storage loss hit, but I didn't need more than a TB anyways as I have a SAS SAN with 8TB. This space was just because I had the drive laying around doing nothing. CPU cooler is the Corsair Hydro Series H80 High Performance Liquid CPU Cooler Liquid cooling system which does the job for the OC I'm doing. I plan to install a dual loop system when I recover some funds from selling my old rig <--- Which I'll need help with in the future as I have never done this before... What I'm trying to understand with the tri fire 6990 + 6970 is the setup thats involved from the hardware and software. Any issues you came across that I may try to avoid? Raid controller is the intel chipset... For the Maximus IV Extreme-Z this is really your only option as it would not let me set a array per controller. What I had to do was the following setup from the board.


Intel controller (Raid Mode)
SATA 6.0 1: Vertex 3
SATA 6.0 2: Vertex 3
SATA 3.0 3: WD Black
SATA 3.0 4: WD Black
SATA 3.0 5: WD Black
SATA 3.0 6: WD Black

Marvel (ACHI Mode)
SATA 6.0 1: Bluray combo drive
SATA 6.0 2: N/A

P.S. My build is complete and up and running minus the new video cards I have recently purchased... Right now im running x2 ASUS Radeon 6870 CF
August 31, 2011 4:19:27 PM

Understood, really is a nice build.

Crossfire has become allot stress free with better drivers as of late. But as your already running crossfire you probably know all that, so disregard the following if it is not what you were asking. The common process is to install one card (the main card so in your case the 6990) then install drivers etc and then put the second card in. This was to address issues of the second card not being recognised unless done this way.

However I have put together a number of crossfire builds in the last month or so and installed them both at once and had no issues. The only thing to note is that your second card may not be recognised until a certain windows update is installed (i forget the exact one) but as you would do this upon loading the OS anyway it isnt an issue just remember that thats the way it happens. You will know because a pop-up box will appear saying the it has detected multiple cards and would you like to view something or other and it will take you straight to the CCC crossfire enable checkbox screen.

Incase you didnt know plug all three screens into the main card (the third via the active display port to DVI (or equivalent) adaptor.

Also I would advise leaving a one slot space between the cards to get a little more air to 6990 and also remember with the MIVE you needs something (sound card or network card or whatever) installed in one of the slots in order to get the PCIe lanes to operate at x16/x16.

Good luck with the build, would like to see some benches when its done.
August 31, 2011 5:25:06 PM

Ninja Pants said:
Understood, really is a nice build.

Crossfire has become allot stress free with better drivers as of late. But as your already running crossfire you probably know all that, so disregard the following if it is not what you were asking. The common process is to install one card (the main card so in your case the 6990) then install drivers etc and then put the second card in. This was to address issues of the second card not being recognised unless done this way.

However I have put together a number of crossfire builds in the last month or so and installed them both at once and had no issues. The only thing to note is that your second card may not be recognised until a certain windows update is installed (i forget the exact one) but as you would do this upon loading the OS anyway it isnt an issue just remember that thats the way it happens. You will know because a pop-up box will appear saying the it has detected multiple cards and would you like to view something or other and it will take you straight to the CCC crossfire enable checkbox screen.

Incase you didnt know plug all three screens into the main card (the third via the active display port to DVI (or equivalent) adaptor.

Also I would advise leaving a one slot space between the cards to get a little more air to 6990 and also remember with the MIVE you needs something (sound card or network card or whatever) installed in one of the slots in order to get the PCIe lanes to operate at x16/x16.

Good luck with the build, would like to see some benches when its done.



I'll see what I can do on the benches, but really now I'm conserned about my motherboard... Seeing other forums and reviews appearantly the only way I can get 16x16 is to use the NF200 lanes, but in bench marking they actually lost performace using these slots apposed to the 8x8, but these are with single core gpu's. So, I'll see which works out best for me... could be 16x16 or maybe 16x8.
September 1, 2011 12:10:13 AM

The performance difference isn't great, basically 1-2% depending on resolution. At eyefinity resolutions you should be getting the better of that performance increase. And yes as I said the only way to enable the NF200 controller is to have something occupying one of the slots. I almost purchased the exact same mobo for my build and was going to get a fan controller to occupy one of the slots to enable the x16/x16.
September 4, 2011 4:32:31 PM

Hi all

ive finally ordered a HD6970 to tri fire with my HD6990 as planned. Ive ordered this one below
http://www.ebuyer.com/280423-powercolor-hd-6970-2gb-gdd...

but was really tempted by this one below again. I was a bit worried that i may not be able to clock the card back to match the HD6990 settings.

http://www.ebuyer.com/280422-powercolor-hd-6970-pcs-edi...

im going to order the Corsair 1200 Watt Pro Series AX1200 in a week or so, so i wont be able to fit the card till then. I didn't want the 6970 to go up in price as i thought they were a bargain.
September 6, 2011 1:49:30 PM

davexxsmith said:
Hi all

ive finally ordered a HD6970 to tri fire with my HD6990 as planned. Ive ordered this one below
http://www.ebuyer.com/280423-powercolor-hd-6970-2gb-gdd...

but was really tempted by this one below again. I was a bit worried that i may not be able to clock the card back to match the HD6990 settings.

http://www.ebuyer.com/280422-powercolor-hd-6970-pcs-edi...

im going to order the Corsair 1200 Watt Pro Series AX1200 in a week or so, so i wont be able to fit the card till then. I didn't want the 6970 to go up in price as i thought they were a bargain.


The AX1200 is a great buy... As for as the 6970 you will be fine with any vendor if you are trying to crossfire. However, you will have to overclock the 6990 to match the 6970 speed or downclock the 6970, but who really wants to do that. As for the heat as these are massive heat generators make sure you have good airflow if not water cooled. The mother board I'm using is the Maximus Extreme-Z and it was worth every penny and is capable of running all GPU cards at x16/x16. So, in a duel 6990 setup it is a must to be running in x16/x16, but as your going for a 6970 like I did you could probably get away with running the 6990 in x16 and the 6970 at x8 and save some money on the motherboard. All and all the setup worked great and went exactly how ninja pants described. So, hopefully this helps let me know how it goes.
September 6, 2011 2:45:37 PM

Hi

I took the advice and got the Asrock mobo recommended earlier in the post by ninja pants. Ive ordered the AX1200 today and should have the PSU and 6970 by Friday.
I tried enabling the turbo option on the mobo and it overclocked the cpu to 4.8. I had to disable it as the system wouldn't boot back up after a shutdown. So my cpu is just running at standard 3.4.

ill post how it goes when i get it all installed.
September 7, 2011 8:13:56 PM

davexxsmith said:
Hi

I took the advice and got the Asrock mobo recommended earlier in the post by ninja pants. Ive ordered the AX1200 today and should have the PSU and 6970 by Friday.
I tried enabling the turbo option on the mobo and it overclocked the cpu to 4.8. I had to disable it as the system wouldn't boot back up after a shutdown. So my cpu is just running at standard 3.4.

ill post how it goes when i get it all installed.



You shouldn't of had any issues of overclocking your processor to 4.8. Thats what I had it at using the ASUS optimized settings for the Maximus IV Extreme-Z. Does your board have some kind of similar settings? If you can manually do the multiplyer as well the BLCK set that to 100 and the multiplyer by 48. Set all power and ram settings to auto. I'm also hoping that the board is somewhat like mine as far as overclocking features go.
September 7, 2011 10:28:51 PM

HI
If you don't use the turbo option to OC using my Asrock it comes with an app that runs through windows. I initially tried to OC the processor to 4.5 as id heard that it was really easy as you said with the multiplier and the BLCK set to 45.

I still had issues running one of the bench mark tests an it kept freezing. In the end i just reset the Mobo CMOS and left it as standard. I cant get on the pc tonight to check exactly but maybe could in the next couple of days, back at work tomorrow.

Well this morning i ended up with a tax rebate, a very un expected one. So being a bloke i cancelled my 6970 and have ordered another 6990. I hope it will be ok with my Mobo running the second card at x8. I hope its not too much of a waste. It was just a case of well its better to go all out now while i had some spare cash than fitting the 6970 and being a bit disappointed and wishing id waited for another 6990.

This does make sense to me. I could change the mobo in the future if really needed but at least i have the expensive bits now, well Friday.
Well i hope ive done the right thing today,
September 7, 2011 11:15:20 PM

The mobo will be fine and its only on benchmarking where you will actually notice the roughly 1% gain you would have by x16/x16.

When overclocking I wouldnt advise using the app that comes with it, do it all in the BIOS so you have complete control over what is going on.

That said, to overclock to 4GHz is simply a matter of adjusting the MULTIPLIER (never adjust the base clock (BCLK), this should always be at 100, unless you really know what your doing, leave it) to 40. To get more than that you will need to adjust the core voltage (Vcore), the basic idea is you increase it bit by bit until it becomes unstable and that's your stability limit. Don't be upset if you cant get 4.8GHz or above, all 2600K's have an inherent multiplier limit, you could be unlucky and it be set to 45 (50% go to 44-45) or you could be very lucky (2% chance) that you can achieve 50+. Sounds like yours should be 4.8 (from turbo mode) which should be achievable with a Vcore around 1.4-1.425V.
September 8, 2011 8:08:37 PM

Hi Ninja pants
Thanks for the reply, got PSU today and the other 6990 is scheduled for tomorrow. Ill try fitting tomorrow night and will have go at the CPU maybe after the weekend.

Can i ask what you use to check the actual CPU speed after Over clocking.

thanks Dave
September 9, 2011 5:56:44 AM

What do you mean by check? The most common tool to verify overclock's is CPU-Z.
September 9, 2011 5:57:11 AM

What do you mean by check? The most common tool to verify overclock's is CPU-Z.
September 9, 2011 5:58:19 AM

Sorry bout the triple post, laptop went a little weird.
September 10, 2011 11:31:37 AM

Hi
Fit the new RAM, PSU and 2nd 6990 last night. It turned into a bit of a nightmare to be honest and i couldn't get any signals from the GPU and eventually had to connect VGA to MOMO port. Eventually after gutting the system found one of the 2pin power plugs not all the way in on the original 1st GPU. (my fault).

Refit it all and with the Xfire bridge in the PC would boot for a couple of seconds then switch off and just repeat.

Removed bridge and got it to boot ok, then installed GPU drivers and finally fit the bridge.

Ran some benchmark checks and my Haven benchmark 2.5 score went from 2026 to 3742. 3D Vantage11 Score went from 8804 to 13464, i did OC the CPU to 4.5 as well with Vcore changed from 1.16 to 1.41.

Later after i left my son on the pc it stopped working after a reboot and i started again this morning. It eventually started up and said it failed to boot several times. I suspected the CPU OC and lifted the Vcore up to 1.42. Ive ran prime 95 for an hour and haven't had any issues as yet.

My son seems to be having issues with games using quad fire, he has been playing dead island (300fps with 1x6990 and <100fps with 2x 6990) , left for dead (performance also seem worse).

Im currently waiting for a new copy of win7 and had read that to run quad fire correctly there are some win updates that ill need, is that correct.

Also is there a specific way to install the cards for it all to work correctly.

September 12, 2011 8:14:37 AM

I would say any stability issues would be due to the overclock and not the graphics card configuration.
In terms of performance, you shouldn't see such a dramatic decrease, although there have been issues with AMD's drivers when using quadfire they seem to have sorted it out pretty well (sure the scalability isnt what you would like but stability wise it is allot allot better), that seems strange.
There are updates you need to install before your pc will recognise crossfire, but as you do following any OS install is get all the critical updates, this wont be a worry, just keep in mind that if crossfire doesnt appear as an option straight away dont automatically assume its a hardware fault.
I would advise running prime 95 for 24 hours (on the combo mode/type whatever its called). Some people even run it for 24 hours on each of the 4 (from memory i think its 4) modes/types.

No specific way to install the cards, if you have it so that they are both recognised then you've done it correctly.
September 12, 2011 12:23:57 PM

Hi

I posted a thread on the forum under AMD graphics as i thought this post had changed to graphic issue with quad fire rather than the original mobo questions. Ive posted some benchmark results on there and the quires about the system performance compared to how i'd hoped it to run with these cards in.

http://www.tomshardware.co.uk/forum/forum2.php?config=t...

The system seems to have set up the cards ok but on eyefinity the FPS seems far to low. I really expected the system to eat up any game i throw at it.

!