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Krisnatharok
PC Builder, Gamer
Premium Member
join:2009-02-11
Earth Orbit

Krisnatharok to drslash

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to drslash

Re: Proposed Mother of All Builds (MOAB)

That's a nice build, I think you'll like the mobo, even if its cost is a little disproportionate for your build... :x

Did you get the black or white Thor case?
Chrno
join:2003-12-11

Chrno

Member

This PSU isn't designed to hold a sustained full load, at least not for long. Recommend you return it and get something with more head room. Would be fine if you are running 2 GTX 680s which I have done on this PSU but 2 7970 is a bit too much...

Krisnatharok
PC Builder, Gamer
Premium Member
join:2009-02-11
Earth Orbit

Krisnatharok

Premium Member

Can you support that with evidence? I've always considered Cosrair's pro/gold PSUs as being continuous at whatever they are rated.

shinjuru

join:2000-10-29
West Coast

shinjuru to Chrno

to Chrno
I'm very interested to know why you're stating this, as well.
Chrno
join:2003-12-11

Chrno to Krisnatharok

Member

to Krisnatharok
There is none. I am basing this on what I see on a day to day bases. If these PSUs are that capable then we would have people running these on servers but I haven't seen them in barebones as of yet. Keep in mind that servers are generally ran in controlled environments and I have not see PSUs not able to run sustained capacity. And by "long" I mean running these at sustained load for 24/7.

I know for a fact that I have no problems running 2 680s on this PSU with CPU OC but I just don't know about the GE 7970. The stock 7970 is rated for 250w so the GE version can't be 250. In an ideal, closed and isolated environment I would say yes, you can run whatever that will draw the rated capacity for as long as you want but sadly we don't and in this case, having a bit of head room is better than none at all. 850w would be ideal IMO.
drslash (banned)
Goya Asma
join:2002-02-18
Marion, IA

drslash (banned) to Krisnatharok

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to Krisnatharok
I got the black case.

Krisnatharok
PC Builder, Gamer
Premium Member
join:2009-02-11
Earth Orbit

Krisnatharok to Chrno

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to Chrno
said by Chrno:

There is none. I am basing this on what I see on a day to day bases. If these PSUs are that capable then we would have people running these on servers but I haven't seen them in barebones as of yet. Keep in mind that servers are generally ran in controlled environments and I have not see PSUs not able to run sustained capacity. And by "long" I mean running these at sustained load for 24/7.

I know for a fact that I have no problems running 2 680s on this PSU with CPU OC but I just don't know about the GE 7970. The stock 7970 is rated for 250w so the GE version can't be 250. In an ideal, closed and isolated environment I would say yes, you can run whatever that will draw the rated capacity for as long as you want but sadly we don't and in this case, having a bit of head room is better than none at all. 850w would be ideal IMO.



1. This is not going to be running a 24x7 sustained load.

2. Let's not discuss what someone believes "ought" to believe based on the lack of evidence--I don't care about what servers use, because, as I've said before, I am not going to be using this as a folding machine or doing anything specific for 24x7.

• Like other brands' "Continuous" rated, I have always considered the high-end units, such as the AX series, and perhaps even the HX series, capable of supplying continuous power at the rated spec.
• That said, my build will do nothing of the sort, it idles at 122w with one GPU, maxes in game below 350w, and can only be artificially pegged at 520w in a LINPACK+FURMARK burn test. That's with the brink OCs (CPU @ 4.6 GHz, GPU @ 1220mhz).
• That 520w max was inflated by 100w by the OCs, so I can probably keep things under 750w max without aggressive overclocks.

Keep in mind these are the power draws at the wall, so knock off 10% for delivered power (using the 90% efficiency rating).

I agree that 850w was ideal, but I didn't feel like buying a new PSU on top of everything else right now. I'll probably get one in a couple months, or if the need to bring back the OCs takes over, but I've had the AX750 for a couple years and it has served me well, so I decided to stick with that for now.

Gordo74
Premium Member
join:2003-10-28
Pittsburgh, PA

Gordo74 to Chrno

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to Chrno
said by Chrno:

There is none. I am basing this on what I see on a day to day bases. If these PSUs are that capable then we would have people running these on servers but I haven't seen them in barebones as of yet. Keep in mind that servers are generally ran in controlled environments and I have not see PSUs not able to run sustained capacity. And by "long" I mean running these at sustained load for 24/7.

I know for a fact that I have no problems running 2 680s on this PSU with CPU OC but I just don't know about the GE 7970. The stock 7970 is rated for 250w so the GE version can't be 250. In an ideal, closed and isolated environment I would say yes, you can run whatever that will draw the rated capacity for as long as you want but sadly we don't and in this case, having a bit of head room is better than none at all. 850w would be ideal IMO.

LOTS of flaws in this argument.

1. You're right. These aren't server grade. Neither are any other consumer level power supply, but the Corsair AX series as well as other's top of the line PSUs such as Rosewill Capstone, Seasonic X series, and the like are as close as you can get. To use this as an argument is like stating that you only would buy a $500 drill even though the $100 one from Home Depot will last you the same number of years for your uses.

2. This will not be sustained load. This is balls-to-the-wall maximum stress that wouldn't ever happen under normal usage. GPUs and CPUs clock down and throttle power nowadays. It doesnt run 100% all the time.

3. Even with VERY AGGRESSIVE overlocks is he getting even remotely close (within 15%) of the maximum (which I think is actually higher because it's rated for CONTINUOUS 750w load, if it happens to peak, I would think a well made PSU can handle it). I think it would be safe to assume he won't be running his cards at maximum overclocks for day to day use. That's just playing with instability and that isn't a function of the PSU.

No point in spending more than you have to just "for some headroom". These things are rated to be near or fully loaded. That is where their most efficient workloads come in.

Krisnatharok
PC Builder, Gamer
Premium Member
join:2009-02-11
Earth Orbit

Krisnatharok

Premium Member

Thanks for your thoughts Gordo. I probably will wait until I am ready to take the full custom loop WC plunge and just go for a 1kw unit. I might adjust the size after doing my WC research, but right now I don't know how much extra power the pump/rads will take to cover the CPU and two GPUs.

That definitely is on the long-term to-do list, and will help me get some life out of this build. Imagine a stable 5 GHz on the 3770K...
drslash (banned)
Goya Asma
join:2002-02-18
Marion, IA

drslash (banned) to Krisnatharok

Member

to Krisnatharok
said by Krisnatharok:

That's a nice build, I think you'll like the mobo, even if its cost is a little disproportionate for your build... :x

I don't mind over buying in this situation a little due to you having very similar setup and that you will be available for questions when I put this together. Your support is worth something to me and you will be rewarded

Moos
Tequilablob
Premium Member
join:2008-12-11
Salt Lake City, UT

Moos to Krisnatharok

Premium Member

to Krisnatharok
I agree that you should be fine with your 750 watt PSU. Looking at the amperage draw of 2 7970's you will only be pulling about 45 amps (depending on your OC). 1 7970 pulling 270 watts equates into 270/12 = 22.5 amps. Adding a second would put you you around 45 amps. I'm Pretty sure that your 12v rail on that PSU is rated a over 60. I think it would be pretty tough to provide the conditions to actually get both 7970's to pull 45 amps. Worse comes to worse you hit your over voltage protection on the PSU and there's your answer. I think you will be more than fine though.

I am interested in seeing your numbers with the kill-a-watt for comparison purposes when you get the dual setup going. My setup with the 2 7950's OC'd to 1100MHZ and an I5-2500K @ 4.4 Ghz was pulling 550-575w max at the wall using a Kill-A-watt. The highest pull during testing was found using 3dmark Vantage. Ive been watching it under various real world conditions and have not seen it higher than this. During the unigine benchmark it barely breaks 500. Gaming is usually in the 400's with games like Crysis 3 @2560x1440 and BF3 at 5760x1080. Max settings on both games.

On another topic, when I added my second 7950 my temps would get up to about 80C on the top GPU. I added more fans and had to play with placing quite a bit. I tried them in about a million configurations changing locations and exhaust/intake. I found the one configuration that works the best is when I mounted a fan to the HDD cage blowing across 2 GPU's. I have the Corsair Carbide 500r, but your Thor looks similar and I think you could mount a fan to the HDD cage too. I'll post some pics if your interested in seeing them. I have not seen the temps on the top GPU get out of the 60C range with this setup.

Your thread is making me want to upgrade motherboard and CPU!

Krisnatharok
PC Builder, Gamer
Premium Member
join:2009-02-11
Earth Orbit

Krisnatharok

Premium Member

said by Moos:

My setup with the 2 7950's OC'd to 1100MHZ and an I5-2500K @ 4.4 Ghz was pulling 550-575w max at the wall using a Kill-A-watt. The highest pull during testing was found using 3dmark Vantage. Ive been watching it under various real world conditions and have not seen it higher than this. During the unigine benchmark it barely breaks 500.

Have you tried the OCCT PSU stress-test? Running Linpack simultaneously with Furmark is probably the most brutal, short of adding an HDD write test with a large file on top of it...
Chrno
join:2003-12-11

Chrno to Gordo74

Member

to Gordo74
It would depend on the intended use of the system. The system would make a great BTC miner and in that case, with 2 cards, you will see some very inflated numbers (sustained). Running hashes with this card will yield numbers very similar to those found while running furmark.

3DMark isn't the right bench to use if you want to find what the card is capable of drawing.

Gordo74
Premium Member
join:2003-10-28
Pittsburgh, PA

Gordo74

Premium Member

said by Chrno:

It would depend on the intended use of the system. The system would make a great BTC miner and in that case, with 2 cards, you will see some very inflated numbers (sustained). Running hashes with this card will yield numbers very similar to those found while running furmark.

3DMark isn't the right bench to use if you want to find what the card is capable of drawing.

Which he openly said in this thread he is not doing. Even if he was, as others have stated, he is not close to the amperage rating on the 12v rail. That PSU is fine for that system for years to come (unless full custom WC is added, which has already been discussed)

Krisnatharok
PC Builder, Gamer
Premium Member
join:2009-02-11
Earth Orbit

Krisnatharok to Chrno

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to Chrno
said by Chrno:

It would depend on the intended use of the system. The system would make a great BTC miner and in that case, with 2 cards, you will see some very inflated numbers (sustained). Running hashes with this card will yield numbers very similar to those found while running furmark.

3DMark isn't the right bench to use if you want to find what the card is capable of drawing.

I don't even know how bitcoin mining works. You should do a PSA/how-to-get-started in this forum.

DarkLogix
Texan and Proud
Premium Member
join:2008-10-23
Baytown, TX

DarkLogix

Premium Member

said by Krisnatharok:

said by Chrno:

It would depend on the intended use of the system. The system would make a great BTC miner and in that case, with 2 cards, you will see some very inflated numbers (sustained). Running hashes with this card will yield numbers very similar to those found while running furmark.

3DMark isn't the right bench to use if you want to find what the card is capable of drawing.

I don't even know how bitcoin mining works. You should do a PSA/how-to-get-started in this forum.

All I know is it uses lots of CPU and GPU power to make hashes.

And it seems the value of a BTC has gone way up due to how more power its taking to get new hashes.

Security NOW breifly talked about it as it seems the DB that used to be the goto one for mining was updated and somehow broke mining.