Thrice the flowrate, how much cooler?

I've got a barton 2800+ running the stock HSF, lapped with paste used. OC HSFs are hard to come by where I'm from, but I can get high-speed Sunon fans that fit the same heatsink. My current fan is a 4400rpm Delta 60x60 that does around 21 CFM. The Sunon I'm eyeing is an 8000rpm 60x60 fan which does 56 CFM. How much cooler will my CPU get? Currently,
CPU Idle: 51C
CPU Load: 58C
Ambient Temperature: ~25C

I'm not hoping for a temperarure of 30C, 'cause i know that thermodynamics doesn't work so co-operatively............

You may see a few C at best. You should consider changing your HSF setup for better results.

Those temps are really high. I would never run my pc over 55C. But thats just a personal preference.
You should just try as hard as you can to find a replacement.

Tyreal said:

Those temps are really high. I would never run my pc over 55C. But thats just a personal preference.
You should just try as hard as you can to find a replacement.

Click to expand...

dont forget he is running stock cooling. That explains the higher temps, which arent really that bad for stock.

Maybe we can help you find a place to buy a HSF.

edit: w00t! 5 stars.

I doubt you will get 30c with the stock cooler, probably more like upper or lower 40's. Also, that fan probably sounds like a hair dryer.

Trice the air can really bring down temps 5-10 maybe. I remember changing a 6cm stock fan with a delta hp 6cm fan and it made a huge difference. Sadly not only in temp but also a lot more in sound :/

Hair Dryer? I already have a 12cm side fan that's as loud as a vacuum cleaner! I sucks 0.49A from the 12V line - that's around 5~6W of power. In fan terms, that's loud! So, getting that 8000rpm fan is alright in terms of the possible noise...........It's just that I really have no alternative HSF available to me here in Bangalore, India. mainly because overclocking is an extremely uncommon practice here, sometimes considered taboo.

I have that 12cm fan because it actually dropped my CPU temps by around 6C !!
Old temps:
idle: 58~59C
load: 64C

new temps with 12cm side fan:
idle: 52~53C
load: 58~59C (only in Prime95 - games pull it only upto about 55~56C)

Now, under these conditions, at an average ambient temperature of around 25C, how well will a 56CFM fan work as compared to a 21CFM fan on the CPU?

Also, my maximum stable clock is 2350Mhz @ FSB 188 (Barton 2800+ @12.5x)
even though I set my Vcore to 1.65 + 10% = 1.82V. I believe this is because in looking at the graphs in Speedfan, the Vcore reading drops as low as 1.74V under Prime95 load. Now, somebody tell me that voltages aren't supposed to crash like this, and that I need a better PSU (currently a Codegen 400W), 'cause I'm sure my processor can go higher is given more juice................

XP 2800+ Barton
Gigabyte GA-7N400E-L
FX 5700 128MB
512MB DDR400 @DDR333
(all at stock now)

Default Vcore overvoltage!!!!!

Oops - forgot to mention that the stupid Gigabyte board I have always supplies a Vcore varying between 1.696V and 1.712V - default overvoltage!!!!!
I checked out a barton 2600+ (1917Mhz) of a friend of mine - his idles at 40C. 40!!!!!!!
Now I'm convinced the extra 0.5V is responsible for raising my CPU temps by at least 4C, but at this voltage, it is stable upto 2250Mhz @ FSB180.

Plan of Action, please?

I personally think you should just rig up a duct with an 80mm or 92mm fan. They will give you much more airflow with quite a bit less noise. I made a temporary one with cardboard to replace a failed 60mm fan on my mother's computer until a new hsf arrived, and it worked quite well. Hell, you could even duct that 120mm to it if you wanted.

Ducting seems kinda shaky..........

The 12cm monster I've got is mounted on the side plate of my chassis - meaning that placing a duct attached to it over my CPU HS while covering my cabinet is gonna be scary. If I don't get it right, I'll have a fried piece of organically pacaged silicon. And I'll have to get it right every time I open the chassis - messy...............

By how much will that 56cfm fan drop my CPU temps? Even if it drops it by 5C , I'm fine with it. 10C would be a dream!

Would someone please tell me if the voltage drop I see in Speedfan is because of my PSU? Or is it something else? I can't get past 2350Mhz 'cause the system cold-boots - I'd say it's the voltage. Also, I noticed that whenever Prime95 shows a failure, there's a corresponding drop in either the CPU or the RAM voltage (whichever is correspondingly being tortured). The system is dead-stable at 2250Mhz @1.7V Vcore.

im sure it will drop your temps quite a bit and my question is what are your case temps?
if the temperature in your case in asywhere near 25C then more airflow through the heatsink will take it down at lest 3-5C. btw have you taken the stock fan grills out? i suggest you do so because thet stop airflow.

temps...

Speedfan reports these temps off the IT8712 IO chip:
50C (CPU)
29C (I think it's the northbridge - not sure though, since only the NB has a HS and may be cooler)
23C (I think it's the southbridge)

So, can I cut the temps to 40C idle by putting a 56CFM fan vs my current 21CFM?

Please, tell me if I need a better PSU - one of my previous posts here has info about the voltage issues I have...............

Have you tried a blowhole and duct to the heatsink? That is the cheapest, easiest and quietest way to drop 5-10C

Also what else do you have for case air flow. I know that you mentioned having a 120mm Intake, but what do you have for exhaust? I know there are fans in the PSU, but most of the time, they are not really strong enough to help out much with case flow. Improving case airflow is one of the best ways to get your temps down. Try finding a fan to mount on the back of the case blowing out, and maybe another fan as intake in the bottom of the front of the case. Having more air coming in would help out quite a bit with dust. Also it may make quite a difference in CPU temps. I was using a stock HSF on an old MicroATX case that I had, and just putting an exhaust fan in the back, with no intake had dropped my temps by about 7°. When I moved into a bigger case, of course the air flow changed quite a bit. I ended up putting a 120 mm fan on the side, and a 92mm in the front, with the same 80 mm in the back of the case as exhaust. My fans on my computer are quite loud, but it does make a difference keeping things cool. Right now I am running about 42° running F@H. Last night when I came home from work, I had noticed that it was running about 37° with a full load also. I think your best bet for the situation would be to improve your case air flow. The amount of change you will see may not be as much as you are wanting, but any drop in temps is a good drop.

2oo slow exhaust fans............

Yup, you read it right - I got two 8cm exhaust fans at the back, but I'd say they're barely any good. When I first got them, they were crimped on the 5V line - they were so slow, you could see them wobbling!!! Obviously, I put them on the 12V line, but they're slow anyway, each taking only about 0.12A. The 12cm side blower did wonders for my temps. CPU dropped by 5C! The monstrosity creates so much air pressure inside my Full-Size ATX cabinet that air can be felt leaking from every gap in the cabinet, even thru my CDRW drive! I'm sure I could do with a better exhaust, but the perforation holes in the cabinet are also too small..........I might drop the temps by 1~2C, I think. Any of you recommend getting a better exhaust after all this? And how about the CPU fan itself?
BTW the blower blows so nmuch air into the computer that putting a duct on my CPU fan might even raise my temps..........

12cm fan - 0.49A on 12V == 0.49*12*0.8 power factor = 4.7W

Cooling is an Art, at least for most of US it is.
While there do exist highly over-educated thermal engineers who are employed to scientifically design cooling systems, I have met none here.

However, there is a lot of experience in the Art of Cooling here, and much has already been posted; here comes my piece.

Air Control is really the key: cooler air to the hot components and then out of the case. Sometimes this is best done with a lot of intake and exhaust fans, sometimes it can be done just as well with a few. Usually keeping the intake and exhaust cfm close to equal results in the best temps, but not always, and many seem to find that having more intake helps keep the case cleaner (I have never seen this myself.) The best way I know to determine general case cooling effectiveness is to monitor temps with the side panel in place and then remove the panel and check again. If the temps are lower with the panel off then your case cooling can be improved.

CPU specific-
More airflow will almost certainly improve your cpu temp; just how much it will improve it is pure guesswork and depends on some other factors:
case temp
ambient temp
type of heatsink
quality of TIM (Arctic Silver and such)
Heatsink mating surface flatness- "lapping" can make a big difference.

If the answers to the variables above are horrible then more airflow will probably have little impact.
If all those conditions are already quite good, and the heatsink has a high fin count, then more airflow can make a big difference- possibly even near the 10c you are looking for, MAYBE.

But it is impossible to be sure on the results; you will need to mess around and Experiment.

Voltage issues- without knowing just how severe and exactly what the relevant points are, I have little to say- not nothing, just little.

How snug is the ATX connector to the mobo? If its loose it can result in a LARGE drop of voltage and/or voltage fluctuations.

A really GOOD psu should handle fluctuating loads pretty well, but they can be very expensive.

Volt mods are possible ofr a lot of mid-quality power supplies and this may also help, if you choose to try them. No guarantees, however!

My suggestion: if the noise doesn't bother you then the faster fan on the heatsink should help a bit, at the least. I have found that OEM sinks can always use a lap-job, though it may not help tremendously. Every little bit helps though, when you are pushing a system hard.

The HSF i'm using is the Processor-in-a-box one (PIB). Came with a Delta AFB0612?C (? - forgot that letter). It's a 4000rpm, 21CFM fan. The sink itself doesn't seem to have too many fins. I have lapped it, but the only thermal compound I could get my hands on was some stuff in sealed paper packets, probably of Chinese origin. While assembling my computer, I touched the CPU die and the old thermal pad with my finger (OOPS!!!! WAS A NOOB THEN, STILL PROBABLY AM), hence resulting with a comfortable idle temp of 64C. HAHAHA! Load temps were 69C. After the lap-paste-side blower mod, though, idle is now 51C, load is 59C.
Got my hands on a couple of better case fans - I'll see what they can do........

OC heatsinks are hard to come by around here (I'm in Bangalore, India). And, I'm a college student with not much to spend (~$80 - might get a PS2 'cause of Gran Turismo 4!).

As for my cabinet wiring - pretty clean. The area around the motherboard is practically free of wiring.

Can any of you out there recommend a good Coolermaster HSF? I do know of a place where I can get them......... but Arctic Silver I cannot - I'll have to use Coolermaster's own..........