Underclocking/undervolting Thoroughbred

[qwertyuiop]

I have a AthlonXP 2700+ Thoroughbred running on a NF7-S v2. It's been overheating a lot lately on normal tasks (haven't cleaned out the fans in a long time) and I decided it was time to get things cool and lower the computer's power consumption at the same time. I have since dropped the vcore to 1.525v from 1.65v (it runs down to 1.47v quite often - seems the nf7s tends to undervolt a bit anyway) and the mult/fsb to 200x10.

Is this combo safe for the CPU/mobo?

the CPU is underclocked/undervolted but the FSB is OCd to 200MHz from 166MHz. The RAM is PC3200 with Vdimm at default since I wasn't OCing that.

My main concern is that the OCd FSB will damage the CPU or northbridge since the Thoroughbred is only supposed to handle 333 and not 400...

Also, is there any better way to reduce power consumption within the processor w/o sacrificing much power. Currently SiSoft notes a 7.5% CPU perf drop and 20% RAM perf increase from an estimated 15W (20-25%) CPU power drop. Will that CPU perf drop be very noticable or should the RAM pickup the slack?

Thanks for any info you can provide!

Edited May 29, 2006 by qwertyuiop

[Honda_Boy]

from my experience trying to underclock my 3000+, the system becomes very unstable. Your best bet to reduce temps is to make sure the fans are clean, and make sure the thermal paste is still in good shape. To fix my overheating prob I just had to buy a whole new fan altogether.

Edited May 29, 2006 by Honda_Boy

[qwertyuiop]

The 3000+ is also a different core from my 2700+. I've made sure to keep it as stable as possible and the Prime95 burnin test seems to be fine w/o any problems/errors so far. Still, I'm not sure what FSB actually does to the processor so I'm a little anxious about burning it out...

Edit: I know WHY I'm overheating (the dust buildup which is caked in nicely in some spots), I'm just too lazy/cheap to fix it

I'd like to keep the Vcore as low as possible, even if I have to reduce the clock speed a bit more since that has the biggest effect on temps. So far I'm seeing 10-15C drop on idle (to 49-52C), 61C full load (F@H) and 64C P95 burnin at 30C ambient temps.

Edit14:Edit mental note to stop making so many edits.

Edited May 29, 2006 by qwertyuiop

[xxkbxx]

The 3000+ is also a different core from my 2700+. I've made sure to keep it as stable as possible and the Prime95 burnin test seems to be fine w/o any problems/errors so far. Still, I'm not sure what FSB actually does to the processor so I'm a little anxious about burning it out...

Edit: I know WHY I'm overheating (the dust buildup which is caked in nicely in some spots), I'm just too lazy/cheap to fix it

I'd like to keep the Vcore as low as possible, even if I have to reduce the clock speed a bit more since that has the biggest effect on temps. So far I'm seeing 10-15C drop on idle (to 49-52C), 61C full load (F@H) and 64C P95 burnin at 30C ambient temps.

Edit14:Edit mental note to stop making so many edits.

Hmm, too lazy to spray out dust - but stupid enough to mess with the Bios when not having too much of a clue .... ?

[qwertyuiop]

Hmm, too lazy to spray out dust - but stupid enough to mess with the Bios when not having too much of a clue .... ? wacko.gif

Gotta love the lack of tact on the internet...

Really though, it's the difference between buying 5-10 dollar can of compressed CO2 or air, finding a hose for a compressor that hasn't been used in a couple years, or dragging the computer to a gas station with an air pump or simply booting into BIOS and reduce power consumption (which I've been meaning to do anyway) to reduce heat.

I've run several hours P95 torture tests each at 166x12,173x11.5,182x11,200x10 at 1.525v without any problem. It will reboot while starting Windows at 1.475v and fail P95 at 1.500v. I'm still running P95 torture test with the FSB now at 200.

I don't change settings within the BIOS without being moderately sure what I'm doing usually after plenty of research or getting a more informed answer from someone else (Pete_C,TT_75,CataCow, others in the TTV days...)

I'm pretty sure I know the repercussions of lowering vcore and clock speed (less power consumption,less performance,more possible instability) but not inceasing FSB at the same time or at that magnitude, which is why I'm asking what effect, if any, it will have on the processor,northbridge, other components (if any) and also if thereis any real world performance increase by doing so (200x10 over 166x12).

If the whole thing is stupid, give me a better way rather than blindly critisizing what I've done. I'd love to know a way of reducing how much power the computer uses and how much heat buildup it makes so I can turn the fan speed down just a bit. It's not like I'll never blow out the dust, I just don't feel like wasting money or wasting half a day looking for the hose. Come to think of it, can I just use a bicycle air pump? I know where that is If so, I'd still like the vcore lower for power savings alone. Are you saying that it's not smart to lower vcore to the lowest point of stability as you would increase it to eke out a few extra MHz when overclocking?

[Honda_Boy]

Q-Tips, also never screw with clock speeds unless you know what your doing. He was kinda being like he was because of the lack of logic you showed to lower your temperatures. The best way to deal with temperatures is always make the HSF is operating correctly. If not, you should clean or replace it. Also it doesn't matter what the core is, messing with the clock speeds and the fsb is bound to have some kind of consequence especially if you do not know what you are doing. Just clean your fan, if that doesn't help then buy a new one. Also leave everything at it's stock settings. You also never told us the temperatures you were seeing. Just leave stuff alone. Boy have I ever figured that one out the hard way.

[qwertyuiop]

Well, i called around and found someone with a working compressor and I finally just did it. Temps dropped again on burn test.

200x10 1.525v not cleaned

61C burn

51C idle

200x10 1.525v cleaned

49C burn

44C idle

166x13 1.65v (stock) not cleaned

>70C burn (reached that in seconds)

64C idle

166x13 1.65v (stock) cleaned

58C burn

51C idle

That's a ~12C drop from cleaning and ~10C (additional) drop from voltage. I'm just going to leave the default for this processor for the time being since there seems to be so much objection to it here and ask somewhere like silentpcreview where undervolting/underclocking is much more common...

He was kinda being like he was because of the lack of logic you showed to lower your temperatures.

I don't really think it's an excuse to be rude. I'm sure that if you're looking to fix something/try something new many people google the heck out of it and try to figure it out by themselves. I've been looking into silent PCs and power conservation for a while now and I figured I could kill two birds with one stone by cutting heat and power consumption at once. The issues I saw with the settings I had was the possibility of PCI/AGP bus coming too far out of spec with the high FSB. The AGP locks in but I couldn't find a setting for PCI so I overlooked it for the time being (not the smartest idea anyway). Also, timings would be looser at higher FSB speeds, which on my RAM is 2.5-3-3-8 vs. 2.5-3-3-7 and i've read severael places that athlons on the nforce2 chipset like the higher TRAS settings. Everything I've read about underclocking/undervolting is mainly the exact opposite of overclocking with a benefit of less heat, much less power consumption, and longer processor life but along with the possibility of instability.

I was hoping to heavily underclock/undervolt it eventually and lower the fan speeds so that I could put it to use as a media server and get a new computer but if it draws as much power as it does now, I can't really do that. Only other real options are to junk it or spend money upgrading to much quieter fans (and PSU) and more RAM for continued operation...

BTW, mind if I ask what happened (OC/UC?) that made you "learn the hard way"?

Also, the CPU fan is spinning slower now (by about 1k RPM) but the machine is much louder. There aren't any obstructions so I can't see what the problem is with it... any ideas?

[TheTerrorist_75]

I think the fan is on it's way out and you need to clean the heatsink and processor then reapply thermal paste correctly. My 2400+ doesn't go beyond 44-46C when filled with dust. It idles at 39C when warmed up. The hottest it ever ran was 50C when the house temperature was above 90F and the heatsink was filled with dust and cigarette smoke.

[qwertyuiop]

hmmm... That's really not what I wanted to hear.

I do remember that it used to run much cooler when I first got it but now my northbridge fan and PSU's intake fan are on the way out as well. The NB fan has seized a couple times already in the past year...

I've built plenty of systems in the past but this is the only one that wants to crap out on me and after only 2 years =/

[TheTerrorist_75]

I had my northbridge fan fail. I removed it and placed an 80mm fan in the side opening of my case pointed at the northbridge. I also have a 120mm fan placed in the side opening of my case blowing on the cards (video & Ethernet). I have replaced 3 fans on my CPU's heatsink. I finally bought a deep 60mm with ball bearings. It works much better and is quieter.

[xxkbxx]

He was kinda being like he was because of the lack of logic you showed to lower your temperatures.

I don't really think it's an excuse to be rude. I'm sure that if you're looking to fix something/try something new many people google the heck out of it and try to figure it out by themselves.

I'm being rude because it's ludicrous to mess with CPU settings when you don't know exactly what you're messing with. I can understand you're interest in cooling down the PC, but the 1st thing you need to do is just clean the thing out. It would be the equivalent of me messing with my car engine (which I have no clue about) because my air filters are dirty.

[qwertyuiop]

Using your analogy, I'd would have thought it more to be like:

You notice that your car's gas mileage has fallen. Upon inspection you find that your car needs a tuneup and your air pressure in your tires is low. Ignoring the need for a tuneup, you opt to inflate the tires to their proper pressure, thereby increasing gas mileage.

I wouldn't be "messing with the engine" unless I went and did something stupid to my processor like physically taking it out and attempting the XP -> XP-M conversion to lower heat/power by enabling PowerNOW!. Something like that, I don't know how/why it works, nor do I have the skill necessary to pull it off, and it's quite risky to do so I would never even consider it.

I've never heard of a CPU dying from underclock/undervolt so I considered it low risk moderate reward, just like fixing the air pressure on the tires would. autneup is better for the longetivity of the car but in a pinch correct air pressures would help.

Even if it's ludicrous, it still helps to not be rude. If someone comes to you asking if they can free up space by deleting the "Windows" folder, don't call them a stupid n00b. Explain to them why you can't and tell them something else to do to clean up space or which folders within the "windows" folder are safe to delete and will clear up tons of disk space. Otherwise, he's liable to get POd and start a flame war and never get the advice he was searching for in the first place... That's just how I look at things when I have to give some sort of "PC Support." There's too many trolls and flamers out there intent on making people feel miserable so it doesn't make much sense for those otherwise rational people to act the same way IMHO.