Just a quick thread to see how many of us are actually undervolting and even underclocking our processors, and why they are. I got a Q6600 for rendering, and promptly overclocked it to 3.3ghz on 1.34v. It rips through most tasks and certainly cut down on rendering times for me, but the power drawn at the wall hits 295 watts on load, and 205 watts idling (measured using a kill-a-watt clone). That's with a x1950 pro, 4 hard drives, etc so it's still pretty acceptable. However when I went home for easter, I realised that due to the overclock my computer was consuming more power than necessary, along with running warmer and a tad loud for me. Next step? Undervolt to 1v (the lowest my board supports) and lock the multiplier at 6 rather than 9 resulting in 1.6ghz. Result? Idling at 120 watts, and load at 175 watts (running orthos and RTLHDRIBL). Performance is essentially the same for most tasks, so it's made no difference to me. The temperature at idle is around 34 degrees on a Thermalright U120E with the fan running at 330rpm, load is 45 degrees with the fan still at 330rpm. If I do need full power (for rendering, dvd authoring, etc) I just reboot, drop into the bios and reload my overclock profile. Less than a couple of minutes later I can be rendering at 3.3ghz. Do any of you do something like this? Is it for power savings, quietness or just to keep the heat down?
I use 'notebook hardware control' software on my lappy to lower voltages - it allows you to set individual voltages for each multiplier, so when your idling at 6x (1ghz for me) you have one voltage, and at you max (12x multi, 2ghz for me) you can have another. The software also lets you set profiles (max battery - always lowest multi, max performance - always highest multi, dynamic switching - multi varies according to load, and battery optimised - where the multi varies but its more biased towards keeping the multi low) that make switching on the fly easy. Unfortnuately theres no way to down (or over) clock the processor though, which means even with lowering the voltage battery life doesn't noticeably increase, even though temperatures do drop a few degrees.
I do actually, though I don't lock the Multiplier. About 50% of the time, especially when I'm at work and the g/f's using it, it's only used as a email/web browsing machine, so there's no reason to have it blisteringly quick. It'd be great if Asus Motherboard utilities weren't so completely shoddy, then I could do it without rebooting. Their Smartdoctor Utility for my EN8800GT is good, however, so when I'm not gaming, all the clock speeds get reduced to minimum. One button click and they're back to default.
NHC is a pretty good bit of kit, I use it on my laptop too. Can't undervolt any lower that 0.95v though thanks to the limitations imposed by Intel on the mobile C2D's. Still pretty funky to see how much wattage the total laptop is drawing though!
i've got my fileserver underclocked, but my bios won't let me undervolt, unfortunately. i really don't need a 3500+ to run apache and samba
I undervolt. My E6550 is running at 1.056v, and that's with very little effort so I assume it can go a fair bit lower. I've played around a bit and come to the conclusion that with the undervolt, it's only using about 35 watts. I might play with it this summer and try to drop it further, but even if the voltage can drop further I don't think it'll have much further impact on the heat. Underclocking, on the other hand, has never appealed to me. If I was planning to underclock, I'd have gotten a slower processor to begin with. That 65 watt thermal design power is only the actual power output of the hottest chip in the range - buying a 1.8GHz chip is exactly the same as buying a 2.33GHz chip and underclocking it to 1.8, except that the underclocked solution costs more. The only time I'd consider underclocking is in something like a server, and then I'd also start with the slowest chip in the range.
I can see where you're coming from. However with the ability to have saved profiles in the bios, it's relatively easy to run underclocked (I save approximately 30 watts by dropping from 2.4 to 1.6ghz) and then suddenly bump it up to standard or overclocked quickly. Do we need to run at standard clock speeds most of the time? It's moments like this I think Speedstep should actually drop the multiplier lower than 6x. By the way, if you want to estimate your reduced power consumption drop, you could always use this. Admittedly a power monitor will give real-world results, but it's better than nothing.
Best underclock i could do was buying an epia board <60w at all times (slow as hell though) On my a64 box i never bothered taking it any lower than the CNQ setting since even at that it would only really get above idle when gaming.
This is one of the reasons I'm still an AMD fan at heart. Their Cool-n-Quiet system drops to something like a 4x multiplier and tiny voltage. My old Sempron system would idle at 800 MHz (drop from 9x to 4x). I look at my current Intel system dropping the multiplier by a single step and wonder why they've even bothered. That's actually one of the tools I used in guessing my 35 watts. Careful, though, because it's got wrong values for 90% of the processors in the list. That site assumes the TDP is the actual stock consumption for everything, when in reality it's only true consumption for the fastest chip in the range. So if you want to calculate accurately based on that tool, choose the fastest chip based on the same core, and underclock it to the speeds you actually use. (For related reasons, it's not capable of generating correct values for any of the low-cache Allendale cores, nor for the new 45nm processors, because the site still assumes 65 watts for all of these, and as far as I know not a single one of those processors actually draws 65.)
Yep, that's one thing I always did like about AMD, good power management. It's a shame it's not so effective for the current AMD chips but without AMD, Intel wouldn't have such efficient processors now. Is it possible to use RMClock to do a similar job with intel chips? Thanks for the info, I didn't realise.
Yeah, I suppose you should be able to. I haven't ever used RMClock, but from what I've read you can set multiple performance states with pretty much any attributes you like.
what do you run your processor at then? I have a 3500+ in my current desktop, which is to be replaced by a laptop for me , and the desktop pc becoming a file server. I have been thinking of underclocking it.
I've got 3 ulta-green and efficient systems, and one power-hog Both of my HTPCs are undervolted, does wonders for cooling especially. One of them is a P-M Dothan 735 setup running stock clocks and 1.0v, with a 2.5" hdd draws <20w from the wall at full load and is 100% passive - genuinely silent and really quite eerie, the laptop drive is in a foam block too. Not cutting-edge, its more than enough to run anything shy of HD video, but this setup is for music only (my version of a squeezebox), and general server duties) The other (the main one in the lounge) is currently running a 780G board with a 3600X2 undervolted, though I've not really played with the CPU much as it is just a temporary until I can get a 4850e next week. Would go down to 2GHz on the 4850, undervolted as far as it will go. Theres potential there to cool it passively (with a ninja mini) if I'm lucky. Currently uses around 45w, hoping to get this down a bit with the new CPU though. (though the TV and sound system its hooked up to pull between 700-1500w in practice, depending on volume & brightness of the scene, so I suppose the HTPC's usage is moot, but meh) My main system on the other hand (I say "main", but it probably gets the least use of anything, the lappy gets the most use, and that uses 15w including the screen), idles at around 350w from the wall and loads a fair whack higher, just to compensate for the others
Look out for the same things as when overclocking, you're lowering voltage instead of raising speed, but the same principles apply. Undervolt a bit then stability test If all is ok, repeat. if not, raise to the last stable voltage. Once you get to the lowest voltage for stock speeds, you can then lower the clock speed (if you're willing to make the sacrifice) and try lowering the voltage further.
Tis exactly what I did. You can find yourself running into the limitations imposed by the board though, I could undervolt further but 1v is the lowest my board goes. At least you won't have to worry about load temperatures...
Is this purely a BIOS sort of thing? I'm not a clocker of any sort but I have a Fileserver running a 3ghz Intel chip that is just way too hot and way to power hungry. Would be useful to underclock that.
i really like the standard OC profiles on my EEE1000 i can have 800mhz, 1.6ghz or 1.8. admittedly the final two could maybe have been spaced better, but the idea works great. something that works so seamlessly for a desktop would be great, the constant rebooting when i want to game puts me off
