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Changing hardware for power/heat reduction

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June 21, 2011 9:46:20 PM

My profile has my current setup, but I'm becoming concerned about the heat it generates that my apartment's A/C has to deal with on hot days. I'm not sure whether to consider my idea an upgrade, a downgrade, or a strange combination of both. I'm aware I could do some things with the power management options in Windows, but I'd rather look at getting some hardware that has lower peak power usage (and thereby generates less heat). Can somebody compare the parts listed below with the setup in my profile and give me a rough idea of how much performance I'll be sacrificing compared to how much power/heat I'll save?

Intel Core i3-2100T
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

BIOSTAR H61ML LGA 1155 Intel H61 Micro ATX Intel Motherboard
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

SAMSUNG P2770HD
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
(this monitor has the component and composite connections I need to connect my game consoles)

Scythe SCKZT-1000 80mm Kozuti CPU Cooler
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
(I chose this cooler mainly because it has a more secure mounting mechanism than the push-pins of the stock cooler; I have no intention of doing any overclocking)

LITE-ON Black 4X BD-ROM 8X DVD-ROM 32X CD-ROM SATA Internal 4X Blu-ray Disc Reader Model iHOS104-08
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

I'll probably also cull my hard drives down to one Samsung Spinpoint F3, and I'll only be able to use 2 of the 3 memory sticks from my current build. Other items not specifically mentioned will be kept from my existing build.

I'm willing to consider suggestions for alternatives, provided the performance, power/heat, and price (including shipping) have all been factored into the suggestions.
a b B Homebuilt system
June 21, 2011 10:01:24 PM

You could probably pull the (about) same temps by undervolting the i7 and directing airflow.
With the 2100T you're looking at about ~60% reduction in absolute performance and ~20% for most games.
June 21, 2011 10:09:10 PM

Heat is not the same thing as temperature.
The internal temperature in my case isn't a big issue since I'm not overclocking. What attracts me to the i3 2100T is the 35W TDP, compared with 130W for the i7 920.
I've seen mentions of saving power by undervolting, but how safe and/or easy is that? Also, could I really get the power usage/heat output down to the level of an i3 2100T by undervolting my i7?
Related resources
June 22, 2011 5:29:57 AM

Do you use SpeedStep? It'll automatically underclock and undervolt it for you at idle. Or is that not enough? And heat isn't the same as temperature, but temperature is a measure of heat energy. They're directly related, lower the heat lower the temperature. I mean for all intents and purposes of this conversation, the two terms are interchangeable aren't they? Either way though, Timop is right in that the processor would be a big decrease in performance. I mean if you don't have a use for the extra performance, then you have nothing to lose.

I really don't think your i7 can be underclock/volted to the level of the i3's 35W though, but it will be much lower when SpeedStep engages. Again if SpeedStep is not enough for what you're looking for, then disregard. And all Windows power management does anyway is put the computer to sleep or into hibernate as opposed to just turning the computer off manually when you're not using it. I just hate to see such performance be set aside for an HTPC and it's lower power consumption lol.
June 22, 2011 2:13:17 PM

arson94 said:
Do you use SpeedStep? It'll automatically underclock and undervolt it for you at idle. Or is that not enough? And heat isn't the same as temperature, but temperature is a measure of heat energy. They're directly related, lower the heat lower the temperature. I mean for all intents and purposes of this conversation, the two terms are interchangeable aren't they? Either way though, Timop is right in that the processor would be a big decrease in performance. I mean if you don't have a use for the extra performance, then you have nothing to lose.


No, they're not interchangeable: with a better heatsink, I could reduce the temperature that the cpu runs at, but I don't see how that would significantly reduce the total amount of heat put out into my room. I won't deny that lower heat leads to lower temperature, but that's a dependency that doesn't work in reverse; lower temperature doesn't necessarily mean lower heat.

I wasn't familiar with SpeedStep, but after a little research, it looks like it only applies to mobile processors, whereas both my current core i7 920 and the core i3 2100T I'm considering are desktop processors. I was figuring the underclocking/undervolting would be done in the BIOS setup (where I could also disable hyperthreading and some of the cores), though Windows 7 advanced power settings has "minimum processor state" and "maximum processor state", which I am willing to try if you think it's worthwhile.

As far as having a use for extra performance, I do some gaming, but mainly role playing games (e.g. Fallout 3, Oblivion, Skyrim (on pre-order)), and I'm willing to take a 20% performance hit considering my power/heat reduction looks like about 40%. I do some multitasking while working from home, but I think that would be limited more by my internet speed than by my cpu.
June 22, 2011 3:20:54 PM

I think I see what you're saying now. Yes, lowering the temp of your CPU via better cooling just means that more heat was dissipated from it into your case and/or room. However, lowering the power usage of the CPU would lower the heat generated and lower the temperature increase of your room. That's what I was talking about and I didn't make that clear in my previous post, my bad. No worries though, I assure you we're on the same page lol.

SpeedStep isn't just for mobile processors though. If you look at intel's spec page for your processor, it has SpeedStep technology. However, it depends on if your board has the SpeedStep option in BIOS, and it should. Take a look in BIOS and see if it does. If so, give it a shot for a few days and see if it makes enough of a difference. Or, if it's already enabled, then you'll know right off that you want more. You should only need to enable SpeedStep, there won't be any options or parameters to adjust as far as I know.

It works the same as AMD's Cool N' Quiet and I use it with my 125W TDP Phenom II 940. It runs stock at 3.0Ghz (200Mhz x 15), 1.5v or so, and will idle at about 40C. But when Cool N' Quiet engages when my machine is idle, it idles at 800Mhz (200Mhz x 4), 1.0v, and around 28-31C. So it underclocks by lowering multiplier and voltage and nets me about a 10 degree celsius decrease in heat output. SpeedStep should accomplish the same for you.

The Windows' minimum and maximum processor state settings only set limits I think. It doesn't govern your CPU, just doesn't let it go under the min or over the max. So technically I guess you could set the max under 100% but if you do that then you technically have a lesser CPU. With SpeedStep, it'll instantly underclock/volt when you don't need it and instantly reinstate stock settings and voltage when you do need it. Always instant and always automatic. Also, if you monitor it with the utility that came with your board, you'll see that the temps drop and increase instantly as well. And in this case, the temps drop because of a decrease in power supplied/consumed and we're both on the same page this time lol. But if gives you a lesser CPU when you don't need anything better and gives you the performing monster you purchased when you do need it. And trust me, with those games you mentioned, you'll need the extra CPU power without the CPU bottlenecking your system to the point of the games not really being playable at decent settings.

Also though, the other components which could generate heat are hdd's and gpu's. HDD's you can only remove as you had mentioned or get cooler operating drives. Maybe an SSD even? But the GPU could be unclocked too. You have a 5770 and ATI claims it has "ATI PowerPlay™ power management technology" for "Dynamic power management with low power idle state." I would assume that's in CCC but I've never really tried it with my 4870. Tell you what, I'll take a look in my CCC later tonight when I get home from work and see what mine says.

With SpeedStep and ATI PowerPlay working together and configured correctly, I think you could notice a big difference in your room's temperature. But just to mention, this would all only be during idle states or lower usage states like web surfing or typing word documents. When you start gaming, all this sh*t will ramp back up to stock settings and beast your games until you go idle again lol. I think it's the most efficient method though.


EDIT: Damn, I didn't realize I typed so much. I hope you find some of this useful, or informative at least lol.
June 22, 2011 4:30:06 PM

I checked my BIOS settings and SpeedStep was already enabled, but I'm not sure how to control it in Windows 7 if it's separate from that minimum/maximum processor state setting. As far as the utility that came with my board, the installer refuses to run under Windows 7 x64. However, I've got a "Kill A Watt EZ", and before, when I had both minimum and maximum processor state set to 100%, it was reading around 167 watts (although it fluctuated a bit) in my work-from-home usage state (vpn, thunderbird, firefox, and a few IM programs running in the system tray). I tried setting minimum and maximum both to 5%, but that only drops my computer's overall power consumption to about 152 watts, which is unimpressive.

I haven't found a good reference for how much power my Samsung Spinpoint F3 and F1s are drawing by themselves, so it's hard to predict how much power I'd save by pulling some of them out. I'm reluctant to get an SSD, because of the price, and sometimes I install 120GB+ of casual games under Program Files (so that I can find out whether a game works properly there without having problems with the UAC)
June 22, 2011 5:20:36 PM

Well you don't really control SpeedStep. It just works itself automatically. Technically I guess you could limit it with the min and max processor states but if you've set both processor min and max states to 100%, SpeedStep wouldn't be able to underclock/volt the CPU since Windows 7 would prevent it. I just tried on a Win7 computer and the CPU wouldn't drop at all, stayed at full stock settings. With the states both set to 5%, I'm not sure how that would affect SpeedStep or the CPU. I don't know if a CPU can really go down to only 5% of it's maximum performance, the one I'm on wouldn't drop to 5%. Setting the max that low might mess with SpeedStep and just freak it out so it doesn't work.

Actually your Kill A Watt might be about right as I bet most of that 152W is still your GPU if it's not under a power saving profile of some sort. Did you ever check CCC to see what options were in the new version of CCC just released this week? And the last I looked, HDD's use like 5-10W of power. They can get warm, but they don't use alot of power.

Yea I agree about the price of SSD's and I figured they would be a little pricier than you wanted for this project. Check to see if there's any updated versions from your board manufacturer. As well as BIOS update possibly. You can use a program called CPU-Z (x64 version) from cpuid.com and it'll show you your clocks, timings, voltages and other info about your CPU, board, RAM, and GPU.

Under power options, use the balanced profile and reset all the settings to default for that profile. Then see if SpeedStep has even been working this whole time by using cpu-z or updated version of the software for your board and watching the clocks and voltages drop.

I'm predicting that SpeedStep has been working and most of the heat has been coming from your GPU. My 4870 never drops below 62C at idle because CCC auto controls my fan and at 62C, CCC drops my fan to 5%. The heatpipes on my 4870 are damn near hot enough to burn me when I touch it for more than a second. But I've never borthered to check CCC for power saving options like SpeedStep for your i7 as I game alot with it. AMD's video cards have a max operating temp of about 105C and they do not have a problem hitting mid 80's or even 90's celsius during gaming. I know mine likes it hot.
June 22, 2011 5:57:38 PM

With default "Balanced" settings, the power readings fluctuate between 156 and 162 watts. CCC is showing me 45C and 35% fan speed at idle; the only gpu-related power saving I can find is to enable AMD Overdrive and set GPU and VRAM speeds both to 600 MHz (the minimum for both, though confusingly current values in CCC and CPU-Z show 400 MHz GPU speed and 900 MHz VRAM speed), and now my power draw is 152-158 watts.

As far as voltage, after doing the above, CPU-Z is showing it mostly steady at 1.048V, with occasional spikes like 1.216 or 1.296V. I think the Core i7 920 is supposed to support voltages as low as 0.8, though according to the manual for my motherboard, the lowest I can set it in the BIOS setup is 0.85 V.
June 22, 2011 7:11:53 PM

Well, wikipedia says that PowerPlay only shows up if using a Mobility, HD3000 or HD4000 series card. So wtf, I don't know why that is. Maybe it's just automatic now too since CPU-Z showed your card currently at 400/900 Mhz and stock speeds are 850/1200 Mhz. So, I guess we would have to conclude that your machine has been using built in power saving features all along. I'm not sure what more you could do with your current setup to lower power consumption and heat output further.

I kind of feel bad now about wasting your time trying out all that sh*t just to find it's been in use this whole time anyway lol. I'm not really sure yet either what hardware would be best to get at the moment either. I do know that the CPU you chose is a popular choice for HTPC's, especially with Intel's new built-in iGPU on die. I'm not sure how it would fair actually trying to play recent or new games on it. New components would require me to research some before making any suggestions.
June 22, 2011 9:17:32 PM

Well, first I'm going to narrow down to one hard drive to see how much power savings that gives me. If that's not enough, I may get a Sandy Bridge processor, but maybe not restrict myself to the 2100T - in terms of idle power consumption, I found in this review that an i5-2400 would only draw a watt or two more than an i3-2100T:
http://www.silentpcreview.com/article1202-page3.html
and another review that showed even an i7-2600K at stock speed only draws two watts more at idle than an i5-2400, and still significantly less than an i7-950:
http://www.bit-tech.net/hardware/cpus/2011/01/03/intel-...
June 22, 2011 9:55:48 PM

Well at least with those Sandy Bridges you'd still be able to get your gaming jollies off :p  At only 2W or so more, it deifnitely be the better idea if you're willing to pay the extra money. Of course the highly popular i5-2500K is there in the mix... in case you ever wanted to overclock, during the winter or something haha.
June 23, 2011 3:41:50 PM

I had some difficulties with the disk-size restrictions when restoring a Windows System Image, and I had to set my BIOS "Configure SATA as" to IDE instead of AHCI, and now my minimum power consumption reading while browsing is 132 W. Two questions before I order a core i7-2600k with the other hardware I listed above:
1. assuming I don't manually overclock the cpu, do you think the Scythe Kozuti will be able to handle it?
2. with that motherboard, do I have to worry about the Scythe Kozuti interfering with other components, such as cooling fins on my RAM?
If no to the first or yes to the second, I'm willing to consider suggestions for alternative coolers or motherboards - for the cooler, I want lightweight with secure mounting, and for the motherboard I want inexpensive since I don't need much in the way of features (I wouldn't use SLI/CF, RAID, or 6Gbps SATA; I might use USB3 if I had it, but I don't insist on it)
June 23, 2011 4:58:47 PM

Really, you use that much less power by using the drives has IDE instead of AHCI?

I'll go ahead and ask why you would want the Kozuti or the i7-2600k?

To answer your questions:

1. According to the review by FudZilla, the Kozuti is best suited for 65W TDP CPU's and lower. Since it only uses an 8cm fan it gets loud trying to cool more powerful CPU's. I think it can do it, it's just much louder trying.

2. From the pictures from the FudZilla review, it will definitely interfere with RAM coolers if they have fins in one position and the other position it looks like it probably will too if the fins are the same width the entire height of the heatsinks on the RAM. There's 2 positions possible to mount, at least on an AMD board.

Here's the review: http://www.fudzilla.com/reviews/item/22929-scythe-kozut...

Actually, on newegg's site listing for the Kozuti, Scythe also states that it can only cool a CPU's with a maximum TDP of 95W and only at max RPM's (3300 rpm's). So, I don't think it'll be very efficient nor a better choice than the stock cooler.

Now I'll add:

1. Getting the i5-2500K will save you $100 and it's the same CPU, only 100Mhz slower. And if you're all about that extra 100Mhz, the i5-2500K is apparently the world's favorite for overclocking right now anyway so you could simply just bump up the multiplier by 1 to get an extra 200Mhz surpassing the i7-2600K by 100Mhz and saving $100 and still be able to use the stock cooler.

2. I'll restate that if you do decide to spend the extra $100 for 100Mhz more in the i7-2600K or save the money on the i5-2500K, I think you're better off with either CPU by using the stock cooler in temps and noise levels (and probably power usage too since it won't have to spin at max rpm's), especially if you're not overclocking (or only barely overclocking).

I'll have to check out boards later. I have to go for now. Also, you could look up the budget builds that Tom's already makes and see if any of those parts interest you. Might find something good.
June 23, 2011 5:26:34 PM

Okay, you've talked me into the i5-2500k instead of the 17-2600k. However, the reason I'm hesitant to settle for the stock cooler is that from what I can find, the stock cooler still uses push pins to mount. I'd feel safer with a heatsink that bolts/screws through the motherboard.

Edit: I had some trouble finding the weight with fan for the Xigmatek Loki, but 426 grams isn't too bad, so I think I'll go with that one.

As far as motherboards, now I'm looking at the ASRock H61M-VS (used in the latest $500 SBM build, looks like better features for the same price as the Biostar I was originally looking at)

Edit: I forgot to include it originally, but I think the reduction in power was from pulling out several of the drives - using IDE instead of AHCI was required to get it to boot properly after restoring the system image, so I can't tell how much difference that detail made to the power consumption by itself.
June 23, 2011 7:17:32 PM

Ooooh ok, gotcha. I forgot you pulled out a couple of drives. And I agree with the push pins, f*ck them, don't use them. I didn't realize that was your reasoning and I fully support it.

According to the reviews from people with i5-2500K's the Loki is great and they all love it. And for $25 with free shipping, I think it's a hard to deal to pass up.

Also the ASRock baord has all great reviews from the 8 reviews that are there. A couple claim it games well for them and another says it has some overclocking options so it's an option if you want it and you cooler will work well with overclocking too. Board is only $60 so seems like a decent deal. It only has 2 RAM slots though so you could only use 4GB or RAM unless you bought a 2x4 GB kit.
June 23, 2011 7:43:32 PM

Thanks for the feedback. I've placed the order.
June 23, 2011 8:11:57 PM

Welcome. I hope it all works out well man.
June 28, 2011 4:44:13 AM

I'm now getting about 86W/40C at idle and 160W/60C under Prime95 cpu load (at stock speed). I think that gives me some overclocking headroom, since I'm willing to allow up to 100W idle and 200W under Prime95 cpu load, though I'm not happy about the recommendation to wipe and reinstall Windows in the I7 - 2600K / I5 - 2500K Overclocking Guide.

My new monitor, after calibrating to 120 cd/m2, draws about 44W, compared to about 120W for my previous monitor. (confusingly, 120 cd/m2 on this monitor looks about as bright as my previous monitor did when reading closer to 240 cd/m2 on the colorimeter)
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