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CPU Bottleneck if using GTX 280 SLI - Please help!

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June 6, 2008 2:36:39 PM

Hi Folks,

I'm purchasing a new system, and I'm trying to understand what its potential limitations may be. I'm concerned that this processor may end up being a bottleneck, due to the SLI I'll be running. Here's the specs:

Intel Q9450 (2.66 GHz OC to approx 3.2 GHz)
ASUS Striker Extreme 2 790i Ultra (1666 FSB?)
8 GB Corsair RAM (1333?)
Vista 64 Ultimate
nVidia GTX 280 x 2 (SLI)
Auzentech X-Fi Prelude 7.1
Integrated NIC
WD Velociraptor 300 GB 10k RPM
PC Power & Cooling 1200W PSU
ASUS DDRW-1814BLT LS SATA Retail
Antec Twelve Hundred case

Please understand that I've never OC'd a PC before; it will be done for me in-store by someone familliar with the process. I'm far more familliar with software than hardware.

I know the SLI 280 GTX might seem like overkill (as will the 1200w PSU) however I may go Tri-SLI at some point and want to be capable should I decide to do so.

My worry is that the CPU will be my limitation. I'll be running in 1920x1200 resolution, with all the AA/AF and options turned to max in most games, so I believe the video cards will get a good work-out, but will the slow clock speed of 2.66 (possibly overclocked to 3.2 GHz or so...) be a bottleneck?

The supplier was suggesting 1333 Mhz memory - should I dump this and go with a faster memory, ie: 1666 or there was another that was 1800 if I remember correctly (however it was very expensive for 8 GB - around $1,000)

If I upgrade to one of the "Extreme" processors with an unlocked multiplier, I would have to spend an additional $700 for the upgrade, and would probably need faster memory as with that processor, the supplier suggested the faster 1800'ish MHz RAM I described above)

I'm also concerned as I don't want to overclock too much, as it gets fairly warm upstairs in our home during the summer, and I'm not sure if overheating may become an issue if I push it too far.

As well, will using an integrated NIC when gaming cause much of a FPS loss due to the CPU having to do more work?

Any suggestions would be greatly appreciated!

Thanks,

Graysdir
June 6, 2008 2:51:05 PM

A Q9450?? Don't worry about the CPU
June 6, 2008 3:08:22 PM

I'd downgrade to Q6600, a single GTX 280, 780i, DDR2, and a Silencer 750W. Then I'd use the $2000 savings to install air conditioning. The PC will be 20% slower or so, true, but it will be much better value for the money.
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June 6, 2008 3:13:05 PM

I doubt any cpu you could throw in there today wouldn't bottleneck those cards somewhat.How much will depend on the game,but i doubt you'll really notice the difference because you'll still have fps coming outta your ears.
June 6, 2008 3:16:09 PM

Quote:
I'd downgrade to Q6600, a single GTX 280, 780i, DDR2, and a Silencer 750W. Then I'd use the $2000 savings to install air conditioning. The PC will be 20% slower or so, true, but it will be much better value for the money.


This has substantial value as both humor and intelligence. I also don't see the point of dropping that kind of cash on hardware that will be outdated within 6 months. If anything (A/C is always nice, though) put the extra cash in a money market or high interest savings acct. and then rebuild/update in a couple years, with more money to save.
June 6, 2008 3:18:54 PM

why do people continue to ask questions about performance of a product that hasn't been released/benchmarked/reviewed yet. How do we know if the processor will be a bottleneck? even if it is, how much higher can you go than the 9450? none higher if you oc. you'll be fine, but since you have so much cash to drop on a pc, give me some.
June 6, 2008 3:21:57 PM

God damn graysdir, price isn't a bottleneck for you huh?
June 6, 2008 3:23:47 PM

aevm said:
I'd downgrade to Q6600, a single GTX 280, 780i, DDR2, and a Silencer 750W. Then I'd use the $2000 savings to install air conditioning. The PC will be 20% slower or so, true, but it will be much better value for the money.

+1 DDR3 is a waste, as is the 790i Ultra.

I believe a GTX280 should be enough on its own to handle 19x12 at max on MOST games.
June 6, 2008 3:37:41 PM

Quote:
why do people continue to ask questions about performance of a product that hasn't been released/benchmarked/reviewed yet


I often have asked myself this. If it isn't out, how are any of us going to know? It also falls into the same bucket that everyone else has posted a "look at my build, is it OK" thread that happens to be the exact same hardware as everyone else. Since when are similar builds going to be getting approval in one thread and disapproval in another? Do some simple searches in the forums for similar topics instead of blindly asking questions that have been answered 100's of times?

Hey, I'm building a new PC, should I get a dual core or a quad core?
June 6, 2008 4:56:36 PM

rubix_1011 said:
Since when are similar builds going to be getting approval in one thread and disapproval in another?

Budget, intended use, location, personal preference (definitely a factor in case selection). (Just playing the devils advocate, but mostly I agree)
rubix_1011 said:
Hey, I'm building a new PC, should I get a dual core or a quad core?

Too true.
June 6, 2008 5:46:05 PM

Thanks for the helpful replies. Much appreciated!

Aevm: I already have A/C in my home, but it's upstairs and since heat rises (and I have to keep the door closed - darn cats!) it gets fairly warm in there! :) 

Rubix: I DID search the forums, however my question is slightly different than what others had asked. I apologize if I wasted your time; but the reality is you could have just ignored my thread if you were too busy to respond thoughtfully. (and you even found time to reply twice - as if once wasn't enough)

On to the matter at hand... It sounds as though I won't have to worry - After reading a recent Tom's article (I love this website) regarding CPU vs GPU being the limiting factor; I was concerned that I would see no improvement between two GPUs and one GPU since the CPU might be such a big bottleneck. Evidently this isn't the case and I'll still see a strong improvement, and by what you folks have stated, it sounds as though a OC to 3.2 will be satisfactory. (Thanks again for that; it helped answer my question)

One last thought: While I realize most of you are jaded and tired of answering peoples redundant questions, try to relax a little bit. I usually don't even post on web forums as I get tired of smart-alec responses ala VN Boards - so cut people a little slack please; and welcome a new poster to your forums.

In any event, thank you to those who replied with helpful responses. I appreciate your time very much!

Grays
June 6, 2008 5:51:16 PM

Well $h!t, I say if you got the money then don't hold back... You get what makes you all warm and fuzzy inside lol

--Arson94
June 6, 2008 6:11:52 PM

WARM AND FUZZY! SUNSHINE AND RAINBOWS! I need a coffee!

One...
June 6, 2008 6:20:08 PM

Quote:
Rubix: I DID search the forums, however my question is slightly different than what others had asked. I apologize if I wasted your time; but the reality is you could have just ignored my thread if you were too busy to respond thoughtfully. (and you even found time to reply twice - as if once wasn't enough)

Quote:
One last thought: While I realize most of you are jaded and tired of answering peoples redundant questions, try to relax a little bit. I usually don't even post on web forums as I get tired of smart-alec responses ala VN Boards - so cut people a little slack please; and welcome a new poster to your forums.


Hmmmm....OK. Welcome to the forums.
June 6, 2008 6:21:12 PM

If that CPU is a bottle neck at 3.2, your ****! Theres nothing better stock, anyhow.
June 6, 2008 6:31:30 PM

3.2 would be a stock QX9770, even a 3.2 dual core wouldn't be a bottleneck for at least a year!
June 6, 2008 6:35:30 PM

Thanks Roadrunner & GamecrazyChris,

I don't know enough about the Intel CPU roadmap, if that isn't already obvious. By your post (and a couple of others) I realize now that this is a newer model that obviously offers more than just the MHz speed. I find CPUs to be very confusing; particularly with the various model naming conventions.

Not knowing much about processors, I thought the speed was what would matter most, and being 2.66 stock, OC'ed to maybe 3.2, and seeing many people OC'ing other processors to 4+ GHz, I thought perhaps I'm putting a slow processor in a system with two very fast video cards, and creating a bottleneck that would make the one of the two cards fairly useless.

I wasn't sure if I needed to migrate to an "Extreme" model or not. Evidently it's unnecessary. I appreciate that you folks cleared that dilemma up for me.

I'm learning a bit more about this; thanks again everyone for their comments.

Grays
June 6, 2008 6:37:48 PM


"Hmmmm....OK. Welcome to the forums."

Now that's better! And thanks. ;) 

Graysdir
June 6, 2008 6:38:09 PM

All right, let's see...

You need a good after market cooler for the CPU. Normally I'd recommend the Xigmatek HDT-S1283 because it's somewhere in the top 10 as performance goes while still being relatively cheap at about $40. But, since money is not a problem for you, you might as well go for the best. There are three air coolers tied for the best, IMO:

Noctua NH-U12P
http://www.ncixus.com/products/27130/NH-U12P/Noctua/

Thermalright Ultra-120 Extreme with a Scythe SFF21F fan

Thermalright IFX-14

All of these are much quieter than average, huge (but you will need a huge case anyway for 3 monster video cards), and around $100. All three can push a Q6600 or QX9650 to record clocks.


The CPU type is mostly between Q6700 and Q9450, assuming you don't want to pay an extra $700 for unlocked multipliers. That would be waste IMO. The Q6700 is a bit slower than the Q9450 at the same clock, but it has a multiplier of 10 which helps when overclocking. The Q9450 will consume less at the same clock (it's 45nm technology, as opposed to 65nm for the Q6700). Either way, you get close to max performance a CPU can deliver these days.


I've never even thought about the kind of PSU needed for 3 GTX 280 cards, TBH. For two 9800GX2 cards, the certified PSUs start at TurboCool 860W and Zalman 850W, but they're mostly 1000W.
http://www.slizone.com/object/slizone_build_psu.html
Assuming that a GTX 280 consumes just as much as a 9800GX2 (it has 240 stream processors instead of 256, but it may have other things instead), I'm guessing two GTX 280 cards will have exactly the same list of certified PSUs. For three of them, there's no list yet, but add 300W since that's the max a PCI-E 2.0 card can get. In conclusion, if the TurboCool 860W can take two 9800GX2s, then the Turbo-Cool 1200W can take 3 GTX 280s. It's not even overkill, it's just about right :) 


You may want to add a storage drive. The WD6400AAKS and WD7500AAKS are pretty good. They will deliver almost the same performance as the Velociraptor if you use large files and they're not very fragmented. Of course, for small files or files spread all over the place the Raptor wins because it finds the tracks and sectors faster.



June 6, 2008 6:59:40 PM

What a phenomenal reply, Aevm! Thanks for taking the time to give me those suggestions. I hadn't taken the CPU cooler into consideration so I'm glad you brought that up. The OEM version doesn't come with a heatsink so I'll pick that one up and add one of the products you suggested. Thanks for the links/part names!

I'm also glad you mentioned the PSU info. To me 1200w sounded like overkill but judging by what you've said, it is definately the correct model to go with.

This all seems a bit overwhelming sometimes. Thanks again for the helpful info.

Grays
June 6, 2008 8:56:59 PM

I have the Q9450 with the Thermalright Ultra-120 Extreme heatsink and it works very well. I currently have it running at 3.2 with no issues. It was very simple to do. I am sure if I wanted I could get it to 3.4 with out stresing it that much. It runs failry cool low 30's while idling and I will hit about 49 degree's celsius under full load.
June 6, 2008 9:00:01 PM

graysdir said:
... I thought perhaps I'm putting a slow processor in a system with two very fast video cards, and creating a bottleneck that would make the one of the two cards fairly useless.

The Q9450 is by NO ONE'S definition slow (save for the criminally insane/delusional - read: thunderman - computer enthusiasts).

I would say what you picked out is great if money is no object. Quad core is the way to go as it will not become 'obsolete' for quite some time (~2 years in the micro-electronics market).

PSU suggestions:
Corsair HX1000
Antec TruePower Quattro 1000
Enermax Galaxy 1000
Silverstone DA/OP/ZU 1000/1200
PC P&C TurboCool 1000/1200

Any of these should be enough (according to my speculation). I did not check connector count on them, so be sure you have at least:
- [3x] 6 & [3x] 8-pin, or
- [3x] 6 & [3x] 6+2-pin

I would suggest the following coolers:
TRUE (& 1600rpm S-Flex or 1900rpm)
IFX14 "
S1283 "
Sunbeam Core Contact Freezer "

Case, I would do one of the following:
Antec Twelve Hundred
Antec P190 (which would eliminate the need for buying a separate PSU)
Lian Li A70
CM RC690
CM Cosmos S (although some say it has cooling 'issues')
ThermalTake ArmorPlus (6000)
Edit: or the Lian Li ArmorSuit P60 or P80 (expensive, but could cool ANYTHING, see: http://fastra.ua.ac.be/en/index.html )
June 6, 2008 9:17:34 PM

Just to clarify a bit: the "Thermalright Ultra-120 Extreme with a Scythe SFF21F fan" I mentioned is the same thing as
"TRUE (& 1600rpm S-Flex)" in KyleSTL's post above. There's a SFF21G (1900rpm) which would pump more air and reduce temps more but it would make more noise. There's also a SFF21E that moves at 1200 rpm and cools less well but you can't hear it.

I totally love my Silverstone TJ-09 case, since we're on that topic. It was designed to handle two 8800GTX cards. I'm not sure how it would handle 3 of those. The GTX 280 will probably be the same size and a bit hotter. It can't be bigger than the 8800GTX IMO because that would cause a customer revolt - very few cases would fit the new card.

Here's a case designed for Triple-SLI:

LIAN LI PC-P80 Black Aluminum ATX Full Tower Computer Case - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16811112159
OK, the price is $426, but if you're spending $2000 on the video cards it's OK to pamper them a bit, I guess.

Edit: I hadn't seen Kyle's edit, about the P80. I guess it must be a good idea, since we both thought of it independently.
June 6, 2008 9:19:32 PM

Thanks Hsarc and Kylestl. And thanks again for your continued help, Aevm. Much appreciated!

Kyle; the items you posted were very helpful and verified that I'll be using the correct parts. I chose the Twelve Hundred and the P&C 1200, so it looks like I'm on target.

Again I just wanted to thank everyone for their help. The whole issue regarding CPU speeds had me concerned and now I feel far better about my purchase. Plus now I know the other components should work fine as well.

I can rest easy tonight!

Have a good weekend folks,

David
!