SFF HTPC, 30W Idle Power, High End Components, i7/H77/7850/8gb

I considered placing this in the CPU section. If appropriate, please consider moving this. Does relate to HTPC and SFF though. Anyway, thanks.

Dear Hexusians,

THE HOLY GRAIL OF COMPUTING? POWER AND POWER-SAVING!

Could we have just one system that is immensely powerful when necessary, but idles at a ridiculously low wattage (and quiet noise levels)?



My situation (feel free to skip):

For the last year or so, I've been using two PCs. My:

• Server: AMD E350. Low power, SLOW!!, mATX-based. 5 green HDDs (inc OS). TV Tuner attached;
• Desktop: i5/H55 ITX combo. Radeon 5750, Intel SSD, 1 WD Green HDD.

The mATX server is on 24/7 (HDDs spin down). The ITX desktop is turned on for productivity or gaming.

My ITX desktop system hasn't been turning on very well as of late, and I've spent about two weeks camping on my 'server'.

So I started thinking: and hence the power vs idle question above.

Intel and ATI/AMD boast about their latest components' gating tech' - so I'm hopeful.



Components considered:

MoBo:

Would like Intel. Convince me otherwise by all means, but arguments need to be compelling. I like the Asus P8Z77-M-Pro (despite its name), for its PCIe 'awesomeness'. More below.

CPU:

I've seen threads on other forums discuss safely getting 4.4 GHz Turbo out of an i7 3770k or i5 3570k on air. I've also seen threads about undervolting one's i7/i5 to get low voltages and power consumption at idle.

However, no threads have mentioned doing BOTH. Some discuss which motherboards allow the best flexibility in setting how low/high you can set multiplier settings, which is a start.

Would like a CPU that idles with only one core 'on' (rest gated) at about 1.6 Ghz (or below?). As required, it can intel-ligently (sorry) use up to 4 cores - at up to 4.2 Ghz (turbo/1 core).

Graphics:

I've read (THG, Anand) that ALL 7-series Radeons have gating technology, such that they can reach 3w idle power consumption (screen off for 10 minutes+).

I'd therefore like the 7850. If I were to stay with ITX it'd be a SFF-friendly 7750, but I can't fit all the HDDs in a small case. :eek:

TV Tuner:

Something PCIe from BlackGold, prob a HTPC-dreamer's BGT3600 (dual S2, dual T2). Needs a PCIe 1x slot. Don't know what this uses at idle.

Storage:

SSD for Windows and Documents, maybe two (non raid). Some 3TB WD Green EVRS HDDs whilst they're cheapest low-RPM per terabyte.

I'd possibly use a Storage controller (maybe HPT 2720?), which is why I need the PCIe x16 (x8) slots. However, this would whack up idle power - wouldn't it?

Case:

Cooler Master 334U-Like case on hand; with 6x 3.5, 4x 5.25. May get a Lian Li PC-A04b, if HD7850 and HDDs fit.

RAM:

Quite like 8GB (DDR3 1.5V), because 8GB>4GB, but not if it increases power significantly. 1W more (at idle) would be accepted.



Your turn:
Having written an awful lot, I wish to know now whether what I want can be done - that is that the components specified can behave at 30w idle.

If not, what modifications, adjustments or compromises do I need to consider?

Many thanks - and I also hope I am not the only Hexusian that finds this subject interesting...

My main PC is used for gaming & general internet browsing etc. It's an Ivybridge 3570k CPU on an Asus P8Z77-V motherboard, with a GTX 670 graphics board. Because I leave the computer on all day & idling for much of that time, I have it set to idle at 1.6Ghz, but ramp up to 4.5Ghz if I'm playing games or video encoding etc. At idle, the whole system uses about 90W (monitor & speakers included), but under full load it goes up to 190W. When you're overclocking it you just need to set an offset value for vCore rather than a set value, & in Windows just modify your power profile to attenuate the clock speed of the CPU. I doubt you could get the components you list down to a 'power budget' of 30W at idle though...maybe an i3 with a low TDP like the 3220T might get close? If you want a very low power server, you might be better off looking at at NAS system, which tend to be more power-efficient than PC hardware.

Hope that helps :)

Don't overclock if you want power efficiency,undervolt and also stay with a mini-ITX motherboard. Also,perhaps you need to consider some of the Xeon E3 models as these lack an IGP and consume slightly less power than normal IB Core i5 and Core i7 CPUs.

These mini-ITX cases will take 5 HDDs:

http://www.fractal-design.com/?view=product&prod=94

http://lian-li.com/v2/tw/product/upl...q08/flyer.html

http://www.lian-li.com/v2/en/product...ss_index=0&g=f

Also,I would be look at a Gold or Platinum efficiency power supply.

Thank you both for your answers.

I've tried to absorb this thread on Anand, but it's perhaps too comprehensive. The graphs in Idontcare's second post suggests his 3770k can reach very low idle watts at 1.6 ghz.

JBG1969, apart from setting your idle clock low, have you anything in your bios? Do you know what your system uses WITHOUT the GFX670 and the monitor and the speakers? 90w is good for all of that, mind you!

I think it was on the thread above where someone said that the T (ie 3220T) models are less flexible than the K models. Although their TDP is less, they can't 'break out of' that envelope. K-enabled chips should still be able to beat (have lower watts) than an unmodified T-variant chip.

CAT5: Good idea about mini-ITX. Ideally, I'd like to continue with ITX. However, I want 2 or 3 daughter boards (inc GFX) so desire mATX. I'll look at Xeon E3, but suspect I'll balk at the prices. Can iGFX be disabled 'physically' (power-gated) on H77?

Mini-ITX may become useful (to me) again when/if PCI Express release their answer to Thunderbird, meaning products using PCIe lanes don't JUST have to be plugged into one's MoBo. These may be able to be switched off after use, and something like a WOL signal be sent to them when needed. We'll see.


Thanks again.

The Xeon E3 CPUs are well priced IMHO:

http://www.scan.co.uk/products/intel...tio-69w-retail

The Xeon E3 1230 V2 is basically a Core i7 3770 non-K with slightly lower clockspeeds and no IGP.

Edit!!

One thing about Anandtech forums,they are VERY pro-Intel and pro-Nvidia down to some of the mods(they are basically a reverse AMDZone and one of the mods is actually a Nvidia Focus Group member),so for general information stay on some of the other forums like Hexus and OcUK and the like.

My MSi board has voltage on Auto. i.e. it ramps up to 1.2v under load at 4.4GHz but goes down at idle.
It's not a mATX though. But I would investigate an MSi board with their new BIOS.

Quote:

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Originally Posted by baius

JBG1969, apart from setting your idle clock low, have you anything in your bios? Do you know what your system uses WITHOUT the GFX670 and the monitor and the speakers? 90w is good for all of that, mind you!

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I've left most of the bios options at their default values, other than those changed for overclocking. I always disable settings for things I'm not using like serial ports or the wifi adapter etc. I haven't checked the power consumption without the 670 installed, but I imagine it would be a bit lower still.

At idle all boards reduce voltage a certain amount. You can undervolt as well, to get an even lower idle power draw, but that will limit the maximum frequency the CPU could work at. So, you might be able to reduce the voltage and still overclock, you just won't get as high an overclock as staying at stock voltages.

If idle power draw is the be-all and end-all, or even the primary concern, you want an AMD FM2 platform. It's plain better at idle than Intel. If performance is more important, then sure, you want an Intel i5/i7/Xeon E3 - but accept that you will be giving up some idle power reduction.

If you need to get a power supply to handle an overclocked iX + 7850, it's going to be massively inefficient when the system is idling with the long-idle features of the 7850. So you're going to be losing some of the benefit of the low powered system anyway.

So personally, I'd edge towards sticking with two systems. Thing is, a low powered server under full load would probably still draw the same, or less, as a desktop system at full idle, and the server will idle at a lower power draw still when it can. So going for the more powerful desktop - even with the lowest possible power draw at idle - is likely to use more electricity. You'll still be compromising to a certain degree. The question is; how much compromise are you willing to put up with?