CPU cooling adventures...

[BaldEagl]

I re-seated my CPU fan/heatsink today.  As I suspected, the thermal grease application wasn't complete across the entire contact patch.  I cleaned it all off then put a couple of drops of arctic silver on the heatsink contact, then I spread it with a plastic putty knife, making sure it was totally covered with a very thin layer.  I was glad that I didn't have to remove the mobo to re-seat it.

So I fired it up and ran a short, ten string (1 string for each core 5 times) Prime95 test at 100% load on both cores.  Temps at stock settings never exceeded 55C.  The test ran 7 minutes.

Then I rebooted to BIOS and set my FSB up to 1600 for a 3.2 Ghz clock and ran Prime95 again.  After five string sets, temps had climbed to 68C and 70C.  The test lasted 6 minutes but the temps were more than I was comfortable with, so I went back into the BIOS and noticed that the auto voltages had re-set CPU Core from 1.2xx to 1.4 volts.  I had documentation from others that at 3.2 Ghz I should be able to get by with 1.3-1.35 volts, so I set it down to 1.3.

The system wouldn't boot.  So I tried 1.325 and booted.  2 strings into Prime95 I suffered a fatal crash and had to hard boot.

Entering BIOS again, I noticed that the low end of the "green zone" on my CPU Core was 1.375 volts so I set it there, re-booted and ran Prime again.  5 string sets, 6 minutes, no problems and temps stable at 62C (ambient room temp 74F).

I'm reasonably happy with that.  I've got a 12-13% gain in speed from the CPU and I can't really think of a real-world application that's going to run my CPU cores at 100% steady.  Idle temps are still in the low to mid 30's and normal operating temps are still under 50C.  Although I've heard of people getting close to 4 Ghz at this voltage setting, I don't really want to tr to clock that high as I'm already linked and synced to my RAM (DDR2 800) at it's performance settings (4-4-4-12 at 2.0 V).

I might play with the voltages again tonight and see if I can get them down at all and remain stable.  If I can I'm sure my temps will drop a little more.

Just thought I'd share.

[Fulmar]

I'm going to give my CPU another 3-4 days burn in on the Arctic Silver and I'll try and reseat and reapply it.

[BaldEagl]

Update:  I got CPU Core voltage to 1.3625 volts (just couldn't quite hit 1.350).  Ran Prime95 20 minutes stable never exceeding 61C on core 1 and with core 2 bouncing between 59 and 60C depending on fan speed.  Whoohoo... just where I wanted it!

[EDIT]  Idle at 33C.

[Getback]

Fulmar, that is the cleanest looking computer I have ever seen! Where did you get the replacement cables? My computer looks like chernobyl on the inside with all the rebar hanging down. It runs a little cooler though.

[Fulmar]

Fulmar, that is the cleanest looking computer I have ever seen! Where did you get the replacement cables? My computer looks like chernobyl on the inside with all the rebar hanging down. It runs a little cooler though.

I used to have anarchy in my cases back in the day.  I don't even consider mine clean to some I've seen*. I used zip ties to keep things together and makes it easier on maintenance.  Modular cable PSU are really nice, this was my first PSU with it and I'll never go back. You can hook up as many or as little power plugs as you need.  The SATA cables are stock one with the board.  SATA really cuts the clutter down.

These are the round IDE cables I use.  I went with 36" because I like to have extra cable slack rather than barely fit tight cable.  They're a good quality construction.
http://www.newegg.com/Product/Product.aspx?Item=N82E16812104403

I just want a reason to replace my 4 year old Plextor DVD-RW for an SATA one...but it keeps on chuggin.'

*The limitations of the design of my case are becoming apparently worse over its 2 year life so far.  Also, the placement of some of the plugs on my motherboard are pretty stupid...see 20/24 Pin connector.

[Getback]

Sweet, I think I may order some. I with you on the SATA DVD. I got one for my mom. Now I'm jealous.

[Gixer]

If your applying thermal compound just stick your finger through a plastic bag and rub it in, all your trying to achive is a tiny layer.

Check your temps against database on the net of same mobo,cpu,cooling and overclock that your seeing the same average wise on temps as everyone else.

Again Intel chips run low voltages, should be high 20's to very low 30's at idle and around 50 at max. If you start off at 1.40+ volts you might not ever get your temps down.

And of course use the very best high end air cooler you can get and fan. Thermalright high coolers are excellent and been using them for few years now. Though check you have the space as they are big.





<S>...-Gixer

[Gixer]

Then I rebooted to BIOS and set my FSB up to 1600 for a 3.2 Ghz clock and ran Prime95 again. 

don't really want to tr to clock that high as I'm already linked and synced to my RAM (DDR2 800) at it's performance settings (4-4-4-12 at 2.0 V).

Didn't you post that you have a E6750 CPU? What multiplier settings are you using to get 3.2Ghz? With a 8x multiplier it should be at 8x400 for 3.2Ghz (should only need stock low voltage) and ram set to 1:1 800Mhz. Ideally this CPU can hit 4ghz - 4.2ghz easy (high end air) with 8x500 and push the ram to 1000mhz if it can take it or pick up some higher speed Ram.

the 4-4-4-12 are timings, BIOS is needed to set the actual Ram FSB set loose timings and then tighten them up once stable at higher FSB.

Also what model Mobo are you using?


<S>...-Gixer

[BaldEagl]

Didn't you post that you have a E6750 CPU? What multiplier settings are you using to get 3.2Ghz? With a 8x multiplier it should be at 8x400 for 3.2Ghz (should only need stock low voltage) and ram set to 1:1 800Mhz. Ideally this CPU can hit 4ghz - 4.2ghz easy (high end air) with 8x500 and push the ram to 1000mhz if it can take it or pick up some higher speed Ram.

the 4-4-4-12 are timings, BIOS is needed to set the actual Ram FSB set loose timings and then tighten them up once stable at higher FSB.

Also what model Mobo are you using?


<S>...-Gixer

E6750 @ 8x multi @ 1600 FSB.  Can't get stable below 1.3625 V.  Stock Intel HS/Fan.  EVGA 780i Mobo.Board wants to default RAM to 5-5-5-16 @ 1.85 V on auto.  Mfg (Kingston HyperX) recommends 4-4-4-12 @ 2 V (where I have it set).

[Fulmar]

Speedfan right now idle.  Ambient right now is about 75F.  Will post updates after changes (this is pre-change)

Temp1 and Temp2 are processor temps.  Temp 3 is probably an error.  The 2nd Temp1 is probbably motherboard. Core0 and Core1 are processor cores.  Core is my 8800 GTS.

Case temp sensors readings:
Northbridge (directly on heatsink): 42C
HDD (directly on top of disk): 32C
CPU (placed on top of heatsink, see pic on first post): 32C

[Fulmar]

Update:
Removed my spare DVD drive.  Removed the side fan filter.  Reattached my homemade chipset fan (after some resplicing and oiling of bearings).

CPU temps have not budged.  But my Geforce 8800 GTS has dropped 5C.  My northbridge now with the 2 fans has droppedd 5-8C.  Motherboard temp is still the same.

The front door on my case may be a major pain to remove and I will forgo that route.  I may reverse the top 80mm to make it an intake fan because the PSU fan I have is on the bottom of the unit.  I know heat rises, but I think the more intake I get, the better.

May replace the stock 120mm fans with some with either more CFM or higher RPM.  Con is that it has to have blue LEDs cuz it wouldnt match my black, sliver, blue computer theme!

[BaldEagl]

Fulmer, D/L either Prime95 or Orthos.  Fire it up and run it on short FFT's for 10-20 mins then report temps.

Right now mine are CPU 60C, GPU <50C, NB <40C at 100% CPU load.  That's with a .5 Ghz OC and stock Intel HS/Fan.  Normal operating temps are lower.

[Getback]

Fulmer, D/L either Prime95 or Orthos.  Fire it up and run it on short FFT's for 10-20 mins then report temps.

Right now mine are CPU 60C, GPU <50C, NB <40C at 100% CPU load.  That's with a .5 Ghz OC and stock Intel HS/Fan.  Normal operating temps are lower.

I'm running Prime95 right now. Wait! I smell something burning, BRB

[Getback]

Geeeze how long does it take for Prime95 to run. 3.5 hours now.

[BaldEagl]

It will run as long as you let it.