Will this PSU SLI 560 Ti's?

[CaptainTom]

Now first just let me state that I, like most PC builders, like to overkill parts to be sure everything works correctly. However I am starting to become curious as to if my PSU can handle a 560 Ti SLI set up...

By my calculations my desktop if SLI'd would contain these parts at this power draw:


-i5-3570k @ 77w

-2x560 Ti @ 340w

-1 TB HDD @ 10w

-2x4GB 1600 MHz RAM @ 10w

-BR/DVD Drive @20w

Total Power: ~460w

Now my PSU is a 600w OCZ modular 80+. If I got 2 6pin y splitters another 560 Ti would fit in my case. At 460w it seems like I could even do some overclocking. So without overkill, will my PSU be enough ?

 

[Rugger]

A system with two 560Ti in 2-way SLI mode requires a 700W PSU with a minimum of 42A on the 12V rails and four 75W 6pin PCIe power connectors. The OCZ modXstream 600W with 42A on the 12V rails is electrically sufficient to power your stock system, but lacks sufficient connectors.

Modern PCs really do use less power than most people think. A 560ti SLI system with a power-hungry i7 965 with extreme overclock pulled 201W at idle and 449W at full load: http://www.guru3d.com/article/geforce-gtx-560-ti-sli-review/14
Your PSU is rated for 504W on the 12V rail. If you use this PSU, then you will be operating at close to 90% rated load at full stress....definitely outside the efficiency sweet spot of 40-70% and not necessarily a good place to be. Will it work? Yes, but at full load you will be pushing the PSU and may experience stability issues. I would closely monitor for heat issues. I would also use a Kill-a-Watt meter to verify power draw at full load and assess load levels/stress on the PSU.

 

[CaptainTom]

A system with two 560Ti in 2-way SLI mode requires a 700W PSU with a minimum of 42A on the 12V rails and four 75W 6pin PCIe power connectors. The OCZ modXstream 600W with 42A on the 12V rails is electrically sufficient to power your stock system, but lacks sufficient connectors.

Modern PCs really do use less power than most people think. A 560ti SLI system with a power-hungry i7 965 with extreme overclock pulled 201W at idle and 449W at full load: http://www.guru3d.com/article/geforce-gtx-560-ti-sli-review/14
Your PSU is rated for 504W on the 12V rail. If you use this PSU, then you will be operating at close to 90% rated load at full stress....definitely outside the efficiency sweet spot of 40-70% and not necessarily a good place to be. Will it work? Yes, but at full load you will be pushing the PSU and may experience stability issues. I would closely monitor for heat issues. I would also use a Kill-a-Watt meter to verify power draw at full load and assess load levels/stress on the PSU.

I mean so far the PSU has been quiet and cool even under full load. The thing is, by the end of this summer I can probably get another 560 Ti for ~$150 and this set up would run better than a 580 which is a tantalizing prospect. I would prefer to not have to buy a new PSU and reconnect everything...

Straight up, in your opinion would I be fine?

 

[amuffin]

REMEMBER You can always use MOLEX to PCIE CONNECTORS! The cards will come with them!

 

[CaptainTom]

REMEMBER You can always use MOLEX to PCIE CONNECTORS! The cards will come with them!

I saw those. I am not sure how to get them to work though. At least when I tried them they didn't. I should experiment with them more though...

 

[JackNaylorPE]

http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-560ti/specifications

Maximum Graphics Card Power (W) 170 W
Minimum System Power Requirement (W) 500 W

So w/ 2nd card, nVidia is recommending 670 watts

Will you see that ? .... no, no where near it. But it's not about staying below 670 watts; it' about delivering stable power at the amperage / load drawn ? Under load, voltage becomes less table which wreaks havoc on overclockability.

The OCZ **Stream units have had widely varying review.....here getting a 7.5 rating
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story3&reid=24

I use 750 watters on 560 Ti SLI builds, 850 if I'm looking for maximum GPU and CPU overclocks. Remember PSU's are most efficient at their 50% load point and, again, if ya not doing serious OC's, that voltage stability shouldn't be an issue. Id give it a shot with your 600 though I'd run OCCT and closely monitor voltages for at least an hour.

 

[Rugger]

I mean so far the PSU has been quiet and cool even under full load. The thing is, by the end of this summer I can probably get another 560 Ti for ~$150 and this set up would run better than a 580 which is a tantalizing prospect. I would prefer to not have to buy a new PSU and reconnect everything...

Straight up, in your opinion would I be fine?

I think it will work, but I would test the setup at full load with no OC. Monitor temps and PSU voltages with software and power draw from the wall using a kill-a-watt meter. The kill-a-watt meter is less than $20 and will tell you how much power your system is drawing at full load. With the draw from the wall you can then calculate how much power your PC is using based on load/efficiency of the PSU. If everything looks good with no OC, then you can OC the CPU and test again.

I simply saying that if you're going to push the PSU, then you need to monitor it to know how hard you're pushing it and make sure that the PSU can handle the loads you want to put on it.

 

[amuffin]

7.5....uh oh, not a good idea..

 

[ko888]

What is the brand and model of the two GeForce GTX 560 Ti's?

Are they factory overclocked cards?

Do you ever run GPU stress testing utilities like Furmark or OCCT GPU:3D or something similar?

If you're planning on using the dual 4-pin Molex peripheral to 6-pin PCIe adapter cables you need to realize that there will be a voltage drop seen by the graphics card due to the extra resistance introduced at the connector junctions. Sometimes this voltage drop is enough to cause the graphics card to not function.

 

[Rugger]

Tom: Is that a GameXstream or a ModXstream?
ModXstream review:
1. http://www.hardwaresecrets.com/article/OCZ-ModXStream-Pro-600-W-Power-Supply-Review/936/9
2. http://www.overclockersclub.com/reviews/ocz_mxs_pro_600w/7.htm
3. http://www.bjorn3d.com/articles/OCZ_ModXStream-Pro_600W/1401.html

 

[ko888]

The OP said it's a 600w OCZ modular 80+.

The only OCZ model that meets those specs is the OCZ ModXStream Pro Series 600W (OCZ600MXSP).

 

[delluser1]

A system with two 560Ti in 2-way SLI mode requires a 700W PSU with a minimum of 42A on the 12V rails and four 75W 6pin PCIe power connectors. The OCZ modXstream 600W with 42A on the 12V rails is electrically sufficient to power your stock system, but lacks sufficient connectors.

Modern PCs really do use less power than most people think. A 560ti SLI system with a power-hungry i7 965 with extreme overclock pulled 201W at idle and 449W at full load: http://www.guru3d.com/article/geforce-gtx-560-ti-sli-review/14
Your PSU is rated for 504W on the 12V rail. If you use this PSU, then you will be operating at close to 90% rated load at full stress....definitely outside the efficiency sweet spot of 40-70% and not necessarily a good place to be. Will it work? Yes, but at full load you will be pushing the PSU and may experience stability issues. I would closely monitor for heat issues. I would also use a Kill-a-Watt meter to verify power draw at full load and assess load levels/stress on the PSU.

True
PC's still use more than just 12v power, with the extra bling guru's system is probably somewhere in the 30-50 watt range of power on the minor rails
And thier power figures are taken from the wall while using a ~90% efficient psu
Those 449 watts of AC power become ~405w DC with a portion of that being 3.3 and 5v power
A bit less stress on the 12v rail than one would think
I wouldn't overclock the cpu and cards and try running Furmark or OCCT with OP's machine ( on second thought I probably would, but that's just me ) but it should be fine for gaming even with some overclocking

 

[CaptainTom]

True
PC's still use more than just 12v power, with the extra bling guru's system is probably somewhere in the 30-50 watt range of power on the minor rails
And thier power figures are taken from the wall while using a ~90% efficient psu
Those 449 watts of AC power become ~405w DC with a portion of that being 3.3 and 5v power
A bit less stress on the 12v rail than one would think
I wouldn't overclock the cpu and cards and try running Furmark or OCCT with OP's machine ( on second thought I probably would, but that's just me ) but it should be fine for gaming even with some overclocking

I did OC my i5-3570k to 4.3 GHz and my EVGA 560 Ti shader to 1900 MHz and GDDR3 ram to 2100 MHz. However I haven't messed around with my CPU or GPU voltages, so it should still be fine right?

 

[10tacle]

I did OC my i5-3570k to 4.3 GHz and my EVGA 560 Ti shader to 1900 MHz and GDDR3 ram to 2100 MHz. However I haven't messed around with my CPU or GPU voltages, so it should still be fine right?

That's a relatively mild overclock at stock voltages (according to your comment about not messing with CPU voltage), so yes, you should be fine. If you were pushing above 4.5GHz and upping the Vcore, as well as overclocking the cards and upping their voltage, I'd be concerned.

 

[CaptainTom]

Best answer selected by CaptainTom.

 

[CaptainTom]

Thanks for all of the help. It seems I am all set to get a 560 Ti whenever I can find one for ~$100 (May not be soon lol)...