My Haswell system and power consumption

[JimmiG]

Just got a kill-a-watt to check the power draw of my new rig. Here are the results:

Idle: 87W
Aida64 FPU test: 215W
Aida 64 GPU + FPU: 309W
Aida 64 stress test with everything checked: 279W

OCCT Power Supply: 324W
OCCT GPU: 222W
OCCT CPU: 197W

In 3DMark, power topped at 210 - 225W depending on the test (Ice Storm was highest).

My CPU is overclocked to 4.3 GHz @ 1.2V Manual voltage (ie. constant 1.2V) and speedstep is disabled. Still quite nice power savings at idle.

It looks like my old Corsair 450W will be enough even when I get a faster GPU, since the VX 450W is rated at 396W max for the 12V rail.

 

[coffeejunkee]

Hmm, not really impressed with those idle numbers. Why did you turn off Speedstep? Did you also disable all C-states? My i5 3570K system idles around 45-50W, diff mobo obviously and diff vidcard, but 30W+ difference is massive in my book.

What I'm also interested in is if you can use the new C7 state considering you have an older psu. It's something that's been conveniently left out in the reviews so far.

 

[JimmiG]

Hmm, not really impressed with those idle numbers. Why did you turn off Speedstep? Did you also disable all C-states? My i5 3570K system idles around 45-50W, diff mobo obviously and diff vidcard, but 30W+ difference is massive in my book.

What I'm also interested in is if you can use the new C7 state considering you have an older psu. It's something that's been conveniently left out in the reviews so far.

I think the GPU makes up most of the difference. Idle power consumption of GPUs has actually gone down over the generations to the point where they draw almost no power at all @ idle. Wouldn't surprise me if the GTX 460 draws ~30W at idle.

Without the CPU overclocked, and with EIST, auto voltage and everything else enabled, idle power is 84W, so I don't think the CPU is to blame. I also have 3 hard drives, 2 SSDs and an old DVDRW in the system plus a bunch of 140mm fans.

 

[Torn Mind]

Hmm, seems like that GPU is really drawing a lot even though this review says it doesn't draw that much:

http://www.xbitlabs.com/articles/graphics/display/nvidia-geforce-gtx-460_6.html#sect0

 

[JimmiG]

Hmm, seems like that GPU is really drawing a lot even though this review says it doesn't draw that much:

http://www.xbitlabs.com/articles/graphics/display/nvidia-geforce-gtx-460_6.html#sect0

It's still 20W at idle, which is more than modern cards:
http://www.tomshardware.com/reviews/geforce-gtx-670-test-review,3217-15.html
Also, mine is a factory overclocked, non-reference PCB model so it's possible they messed with the idle voltages and frequencies. I might be able to score a GTX 670 next week at a good price so we'll see then.

C7 seems to work fine. From what I understand, as long as you have a few fans or hard drives or whatever on the 12V rail, it's not even an issue.

http://www.corsair.com/us/blog/haswell-compatibility-with-corsair-power-supplies/
My PSU is listed as "Likely compatible — currently validating", but its bigger brother, the VX550W is 100% certified. If it doesn't work, just disable it. It only saves 3.1W, which is really only relevant in a laptop.
http://www.legitreviews.com/article/2217/3/

 

[coffeejunkee]

It's still 20W at idle, which is more than modern cards:
http://www.tomshardware.com/reviews/geforce-gtx-670-test-review,3217-15.html
Also, mine is a factory overclocked, non-reference PCB model so it's possible they messed with the idle voltages and frequencies. I might be able to score a GTX 670 next week at a good price so we'll see then.

C7 seems to work fine. From what I understand, as long as you have a few fans or hard drives or whatever on the 12V rail, it's not even an issue.

http://www.corsair.com/us/blog/haswell-compatibility-with-corsair-power-supplies/
My PSU is listed as "Likely compatible — currently validating", but its bigger brother, the VX550W is 100% certified. If it doesn't work, just disable it. It only saves 3.1W, which is really only relevant in a laptop.
http://www.legitreviews.com/article/2217/3/

It's likely mostly the vidcard yeah, you have Golden Sample I see now, could well use 10W more than reference. You also have 1 more hdd than me, compared to newer models the 640GB one probably also uses quite a bit. According to this review your mobo doesn't do too bad: http://uk.hardware.info/reviews/444...5-energy-consumption-idle-avge-over-5-minutes (but that's using igp and only 1 ssd)

What you say about C7 is what I thought too, as long as there's some load you should be fine. Maybe for psu's with dedicated cpu 12V rail it is a problem. 3W isn't much though, although 13% sounds better. On the other hand, cpu's were already quite good on idle power so taking 3W off of what was not much already is still impressive.

Edit: ran the AIDA fpu test on my 3570K at 4.3 GHz (1.176 vcore) and power use was 148W. That's a lower vcore and no HT but I don't think that should make for a 67W difference? Or would it have to do with AVX2? Anyway, the pre-release slides had me enthusiastic but it as it turns out DT Haswell is a bit disappointing in the power saving department.

 

[JimmiG]

Well, the new GTX 670 is installed

Idle remains pretty much unchanged at 86W overclocked. Edit: I let it sit for a bit longer at the desktop and it dropped to 78W.

OCCT PSU Burn is now 392W, up from 324W with the GTX460 1GB. No worries with my 450W PSU, as it's rated for 396W on the 12V rail alone. The system requirements of the GTX 670 call for a 500W PSU with at least 30A on the 12V rail, but my 450W has 33A. I did have to use a Molex->PCI-E 8-pin adapter though, since the PSU only comes with one six-pin PCI-E.

Not sure why the idle is relatively high. I do have 3 HDD's, 2 SSD's, a DVDRW, a Delta1010LT professional audio card, and 8x140mm fans.. Maybe more modern PSUs are more efficient at idle, or maybe 230V outlets vs 120V in the US has something to do with it. Could be an inaccurate K-A-W for all I know.

 

[coffeejunkee]

Well, I didn't expect 'a bunch' to be 8 fans. In general they don't use a lot of power but there's still quite some variance. Noctua fans are especially good at low power, like 0,5W...others use up to 5W or even 10W for some highspeed models. The OZC ssd may use quite a bit as well.

But if you can be bothered, unplug everything and run with the igp for a baseline.

 

[dualsmp]

Generally you can enable speedstep if you are not going for max overclock. You would probably be in the 40-50w range at idle with speedstep enabled.

 

[coffeejunkee]

OP already tested at stock with eist enabled, idle power was 84W. And actually eist doesn't do that much if you already have c-states enabled.

According to Intel guys Haswell ultrabooks would use 20x less power, but for the desktop it's just a few Watts less.

 

[JimmiG]

With the other C-states, entire unused cores are powered down anyway. Speedstep messes with DPC latenciy and causes other problems IMO, especially with tasks that put a variable load on the cores rather than being either 0% or 100%.

I guess I did kind of go overboard with the fans LOL. There are two intake fans in the front, one in the bottom and one in the side panel - One exhaust fan in the rear and one in the top. The CPU cooler has an additional two 140mm fans. The video card also has 2x80mm fans and the PSU of course has its 120mm fan. They all run at low RPM when idle though (either via PWM or @ 7V for those connected directly to the PSU).