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Help finding a PSU for my potential 4870 crossfire system.

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July 4, 2008 9:04:56 AM

Hello all,

I looked for over 3 hours last night on the egg for the right PSU for my system. What I am looking for is the right watt PSU that has at least
4 x 6 pin Pcie connectors for the possibility to run crossfire with duel 4870. I do know that the 4870 takes two 6 pin Pcie slots so for duel I would need a minimal of 4 with the PSU, at least that is what I gathered. Also I was hopeing to find one that was modular, seeing how they realy help with wire managment and all. The only other thing I can think of is to make sure the cables will be long enough in my ThermalTake Armour + Full tower case. Here is my rig......Thanks!!

ThermalTake Armour + Full Tower
GIGABYTE GA-X48-DS4
Intel Core 2 Quad Q9450
G.SKILL 4GB (2x2GB) DDR2 800
PSU (UNKNOWN)
Western Digital 640GB HD
ZEROtherm Nirvana 120mm CPU cooler
ZALMAN VF1000 VGA Cooler
OCZ Freeze Extreme Thermal Compound
SAPPHIRE HD 4870 ( Subject to change if needed)
Acer 24" Monitor
Microsoft Windows Vista Home Premium SP1 64-bit
Related resources
a b ) Power supply
July 4, 2008 1:33:01 PM

Yes, 6+2 can be used as just 6.

That means the TPQ-850 will do too, because it has 2x6 pin and 2*(6+2).

I'd prefer the Antec TPQ-850 over those other two. Listen to WR2, he knows his stuff :) 

Besides, the TPQ is $80/$90 less than those other two right now at newegg after shipping and rebates.
July 4, 2008 2:20:57 PM

I checked out the Antec TPQ-850 and the reviews were not good. That kinda scares me away from it. Also it only has two 6 pin Pcie and two 8 Pin Pcie. I do think i need one with 4 x 6 Pin Pcie. Check the reviews out for your self and tell me what you think. Thre price is nice.
http://www.newegg.com/Product/ProductReview.aspx?Item=N...
Its coming down to the wire. I have to buy today and this is the only thing holding me up. I leave Afganistan soon not much longer thank GOD!

DeepSea
July 4, 2008 2:27:48 PM

I own a TPQ-850 and I can say that is a a great deal for a great power supply. The people who complained about the 12v rail output have nothing to complain about now since I believe the issue was fixed with a recent driver update. You don't even need to worry about that since you are going the crossfire route with ATI cards.

The 8 pin PCI-E plugs do convert to 6 pin ones. The extra 2 pins on the 8 pin connector detach.

My advice is to give the Antec a chance. I doubt you will be disappointed with your decision.

I will try to answer any other questions about the Antec TPQ-850 since I do have the first hand experience.

William
a c 139 ) Power supply
July 4, 2008 3:04:49 PM

The Antec TPQ-850 "8 pin" connector:


WilliamLEJA is right about the large number of "problems" that dealt with Nvidia video card driver issues.
If you take those out of the picture its not very much different NewEgg reviews than the Thermaltake W0131RU.
For every unhappy camper there are probably 3 or 4 satisfied users. There is no "quality control" for the NewEgg customer reviews. I'd weight the JonnyGuru review as a much more accurate picture of the PSU's ability and quality.
It's actually a very good thing to see the Manufacturer Rep being actively involved in making the customer happy. That's pretty rare.

July 4, 2008 3:06:40 PM

I hate to be a killjoy, but the power requirement for a Crossfire of 4870 cards may well take a very large PSU, much larger than the 850wt PSUs being suggested.

http://www.anandtech.com/video/showdoc.aspx?i=3341&p=22

"4850 and 4870 CrossFire both require large and stable PSUs in order to play actual games."

And further: http://www.anandtech.com/video/showdoc.aspx?i=3338&p=5

"With two 4850s paired up in CrossFire, we once again ran into issues with our power supply. Our 1000W OCZ EliteXStream wasn't always enough for the dual-GPU setup and in Call of Duty 4 our system rebooted in the middle of our test at 2560 x 1600. Thankfully OCZ sent us a PC Power & Cooling Turbo Cool 1200W unit that is certified for use with GeForce GTX 280 SLI, and if it works on that beast, it had better work with a pair of 4850s in CrossFire.

The PCP&C unit is quite loud as we mentioned in our review, but it got the job done, we were able to run all of our benchmarks without a hiccup after swapping power supplies. Despite AMD's small-GPU strategy, power consumption on multi-GPU configurations is still just as much of a problem as it is for NVIDIA."

That's right, according to Anandtech, a 1000wt PSI wasn't big enough, they had to install as 1200wt PSU, and that was for a pair of 4850 cards. Crossfiring a couple 4870 card could be expected to be worse. Of course, this may be an anomaly and Anandtech merely had a bad 1000wt PSU, but it should be a warning that these cards are hungry.
a c 147 ) Power supply
July 4, 2008 3:13:25 PM

How much value is there in a modular PSU if you are going to use most of the leads anyhow?

I suggest the PC P&C silencer 750. http://www.newegg.com/Product/Product.aspx?Item=N82E168...
At $139 after rebate, It looks like a better unit to me. 60a. single rail, Crossfire certified, for two 8800GTX class cards.
a c 139 ) Power supply
July 4, 2008 3:17:40 PM

sailer said:
That's right, according to Anandtech, a 1000wt PSI wasn't big enough, they had to install as 1200wt PSU, and that was for a pair of 4850 cards. Crossfiring a couple 4870 card could be expected to be worse. Of course, this may be an anomaly and Anandtech merely had a bad 1000wt PSU, but it should be a warning that these cards are hungry.


Actually I think Anandtech showed quite clearly that a CF 4870 system would run nicely on a 600W PSU - the same size as recommended by the video card Manufactures. There is no way Sapphire would recommend a 600W PSU if it wasnt able to get the job done.
http://www.sapphiretech.com/us/products/products_overvi...

More than likely it was an issue with the OCZ powersupply and since it affected both 4870 and 4850 tests chances are it too was driver related.
July 4, 2008 3:22:23 PM

sailer said:
I hate to be a killjoy, but the power requirement for a Crossfire of 4870 cards may well take a very large PSU, much larger than the 850wt PSUs being suggested.

http://www.anandtech.com/video/showdoc.aspx?i=3341&p=22

"4850 and 4870 CrossFire both require large and stable PSUs in order to play actual games."

And further: http://www.anandtech.com/video/showdoc.aspx?i=3338&p=5

"With two 4850s paired up in CrossFire, we once again ran into issues with our power supply. Our 1000W OCZ EliteXStream wasn't always enough for the dual-GPU setup and in Call of Duty 4 our system rebooted in the middle of our test at 2560 x 1600. Thankfully OCZ sent us a PC Power & Cooling Turbo Cool 1200W unit that is certified for use with GeForce GTX 280 SLI, and if it works on that beast, it had better work with a pair of 4850s in CrossFire.

The PCP&C unit is quite loud as we mentioned in our review, but it got the job done, we were able to run all of our benchmarks without a hiccup after swapping power supplies. Despite AMD's small-GPU strategy, power consumption on multi-GPU configurations is still just as much of a problem as it is for NVIDIA."

That's right, according to Anandtech, a 1000wt PSI wasn't big enough, they had to install as 1200wt PSU, and that was for a pair of 4850 cards. Crossfiring a couple 4870 card could be expected to be worse. Of course, this may be an anomaly and Anandtech merely had a bad 1000wt PSU, but it should be a warning that these cards are hungry.


Look at the total system power use in those charts - it shows that under load the entire system used less than 350W with the 4850's in crossfire.

I somewhat doubt that the power use of the video cards themselves could be the problem, since that would entail power use spikes of more than double the total wattage of the entire system (which would indicate a serious defect unrelated to general power use).
July 4, 2008 3:36:26 PM

I'm actually quite skeptical about the PSU problem that Anandtech had, but merely relayed their experience. I have a Thermaltake Toughpower 850wt and had planned to get two 4870s and Crossfire them, but decided to look for more reviews that either confirmed the problem that Anandtech ran into, or showed that it was just a random occurrence. But I thought it would be good to pass on the information from Anandtech just in case it is true. Yes, I know the charts don't match with the PSU problem, which ends up with thoughts of there being a driver problem or a bad OCZ 1000wt PSU that was first used. It could also relate to the screen size being tested, 2560 x 1600, which caused the cards to malfunction and draw too much power. Lots of unanswered questions, but a situation that did develop and that should not be ignored.
July 4, 2008 5:54:25 PM

Hell I might end up with 2 4870s with a PC P&C 750w running them.
July 14, 2008 7:50:41 PM

I have the TPQ850 and have not had any issues with it. It is actually a nice power supply and is very quiet.
July 17, 2008 5:13:31 AM

i donlt know if it was wise but i was thinking of getting the 620hx for my 4870 crossfire build so thats a q6600 a 640gb hard drive 5 case fans + cpu cooler 4gb ram and 1 optical drive on a p45 chipset.
so yo guys think the 620hx will do?
July 18, 2008 11:51:53 PM

You'll probably be in the 85% load range with the 620 hx, and you have to consider in time the psu looses some of it's efficiency, so if i were you i'd get the corsair 750 or pc p&c 750 just to be future proof. Both are great values and will keep your rig running with no problems.

"With two 4850s paired up in CrossFire, we once again ran into issues with our power supply. Our 1000W OCZ EliteXStream wasn't always enough for the dual-GPU setup and in Call of Duty 4 our system rebooted in the middle of our test at 2560 x 1600."

I have a haaard time believing that, yes they are power hungry gpus but i'm afraid that if two 4850 in CF eat 1200 W then for gtx 280 sli you would need a nuclear reactor :D 
Besides i have a friend with two 4850 in CF and they run perfectly well powered by a 650W Corsair under stress.
July 19, 2008 1:37:10 PM

I'm running two 4850's in a crossfire config and I can say from experience with power supplies its quality over wattage. Last week I had to replace a 700 watt power supply. I only went up to a 750 but got a thermaltake toughpower. I've put it under every load I can think of and unlike the 700 watt the 12v rail doesnt fluctuate under heavy load. The main thing I think is with dual graphics cards its good to have a supply with multiple 12v rails. Based on the wording of my manual when plugging in my video cards I with the toughpower I had to make sure I used the cables in the right order, this way the load is divided over mulitple rails properly.
August 10, 2008 6:12:14 PM

sailer said:
I hate to be a killjoy, but the power requirement for a Crossfire of 4870 cards may well take a very large PSU, much larger than the 850wt PSUs being suggested.

http://www.anandtech.com/video/showdoc.aspx?i=3341&p=22

"4850 and 4870 CrossFire both require large and stable PSUs in order to play actual games."

And further: http://www.anandtech.com/video/showdoc.aspx?i=3338&p=5

"With two 4850s paired up in CrossFire, we once again ran into issues with our power supply. Our 1000W OCZ EliteXStream wasn't always enough for the dual-GPU setup and in Call of Duty 4 our system rebooted in the middle of our test at 2560 x 1600. Thankfully OCZ sent us a PC Power & Cooling Turbo Cool 1200W unit that is certified for use with GeForce GTX 280 SLI, and if it works on that beast, it had better work with a pair of 4850s in CrossFire.

The PCP&C unit is quite loud as we mentioned in our review, but it got the job done, we were able to run all of our benchmarks without a hiccup after swapping power supplies. Despite AMD's small-GPU strategy, power consumption on multi-GPU configurations is still just as much of a problem as it is for NVIDIA."

That's right, according to Anandtech, a 1000w PSI wasn't big enough, they had to install as 1200wt PSU, and that was for a pair of 4850 cards. Crossfiring a couple 4870 card could be expected to be worse. Of course, this may be an anomaly and Anandtech merely had a bad 1000wt PSU, but it should be a warning that these cards are hungry.

I hate to tell you this but who ever did that testing had a bad PSU to begin with. There's no way on God's green earth that 2 4850's need 1000w+ PSU. 600w or more is enough to run those two and 650w would be enough for two 4870's in CF. So get some different tests.
August 11, 2008 1:49:35 AM

Not completely, there are a couple of 750W psus and a 650W psu
!