New to overclocking with temp questions

[Philosophytutor]

I am new to overclocking and I started out by reading as much information I could find. One of the first guides I read was the “Core 2 Quad and Due temperature Guide – by CompuTronix.” After reading the guide I did some experimenting and my experiences are not matching the guide. I am sure I am doing something wrong I am just not sure what. If you can, please help me out.

The first thing I did was to follow the guides instructions and slow my computer down to get idle temps and then set it back to normal and get load temps. The problem is the temps are not where I (and the guide) seem to think they should be.

Results

Tcase = Idle 30 / Load 49
Tjunction = Idle 30 / Load 50

Variables

Ambient = 22
Chipset = 775 LGA
C2D = E6750
CPU Cooler = AVC PENTIUM 4 DUAL CORE HSF Z9H741K001
Frequency = Idle 1.8ghz / Load 2.6ghz(Stock)
Load = Prime95
Motherboard = EVGA NFORCE 680I SLI MB REV D
Stepping = Revision G0
Vcore = Idle 1.1 / load 1.4 (Stock)

The first question I have is what kind of cooler do I have. I bought this computer from Alienware a while back and that is out of my system info off of their website. I just cant find any information on it other than a German website which will sell me one (unfortunately the site is in German so I cant make much of it).

Perhaps I am wrong but looking at the heatsink/fan and considering it was from alienware I would hope it is better than stock. But if I use your formula with the heatsink as the unknown variable I get 8. So either my heatsink and fan sucks (is worse than stock Intel) or speedfan is reporting my temps high.

Also under load I am not getting the 5c separation between Tcase and Tjunction mentioned in the guide. Even if I push my computer a bit (I overclocked it to 3.6ghz/1.4v) and after running prime95 for an hour (no errors) I got only 2c separation between Tcase and Tjunction. (69c/71c).

What is going on with my system?

 

[CompuTronix]

What is going on with my system?

Philosophytutor,

There's nothing unusual about your rig. Don't expect your pre-calibration temperatures or your Tcase to Tjunction Gradient to be correct, as they rarely are.

I Googled your cooler and reviewed the images and specifications. It's a good quality mid-range class heat pipe tower style cooler with a powerful, high CFM 4000 RPM 92mm fan, so the cooling performance should be decent. Therefore, the following applies to your rig:

X = 2, and Y = 4, so (2 + 4) / 2 = 3

Z = 3 + 22c Ambient = 25c Tcase Idle

Re-calibrate Tcase Idle and Tjunction Load accordingly.

Comp

 

[Philosophytutor]

Thanks you very much for the detailed answer and the detailed guide. I have made the adjustments you suggest in your guide. Things look much better now.

I had one more question about temps. In your guide the temperature specifications for my chip (C2D E6750) are

Tcase/Tjunction
--70--/--75—75—Hot
--65--/--70—70—Warm
--60--/--65—65—safe

Right now with my chip overclocked to 3.6 (by bumping the FSB) I am getting Idle temps of (Tcase/Tjunct) 44/46 and load temps of 60/65. So I am currently in the safe scale. How much farther can/should I push my chip? Basically when do temps become bad for the chip? Do I have to go past the hot before I can damage or if I run it at warm for extended periods of time will that do damage?

Thanks again for all the help.

 

[CompuTronix]

I can not, in good conscience, recommend testing at "Hot" Scale, however, at Standard Ambient 22c, if Prime95 Small FFT's is stable for at least 8 hours, while not exceeding "Warm" Scale and Vcore Load 1.5 in SpeedFan's "Charts" or CPU-Z, then your rig has an optimal overclock. Understand that once temperature and stability testing have been completed, there are no games or applications you can run which will approach the steady-state 100% workload of Prime95 Small FFT's. This means that as long as your environmental conditions remain constant, your case and cooler don't become clogged with dust, or your CPU fan doesn't fail, then your temperatures will never again reach "Warm" Scale.

Regarding CPU longevity, 24 / 7 overclocking, and the topic of elecrtomigration, there is far too much concern being expressed in the Forums over what is essentially a non-issue. As long as you don't exceed Vcore or Thermal Specifications, the long term effect of overclocking is typically that many years hence, when your rig is has long since become obsolete, the BSOD that you see one day will simply mean that you must choose to either slightly increase Vcore, (if you have the head room), or slighty decrease your overclock, in order to regain stability. It is indeed rare to ever read anywhere on the internet that someone's old processor has died from overclocking, let alone from old age.

Enjoy your rig!

Comp

 

[sportsfanboy]

As you may or may not know, heat is not the only killer. Higher Voltage values than recommended max can kill your cpu before it's time. 3.6ghz is a very respectable overclock for that chip. I would say push it if you still have the need to, but keep the voltage under 1.5.

 

[Philosophytutor]

@ CompuTronix
Thanks again for the quick and detailed answer. I may try to push my computer a little bit more but right now it seems to run pretty good. I pushed the FSB to bump the chip to 3.6ghz and I was actually able to back down the Vcore to 1.3875 (Auto sets to 1.4). I ran Prime95 for 12 hours last night with no errors and the temps never got above 63/68

@Sportsfanboy
Thanks for the advice. Many of the guides I have consulted said the same thing. Right now I am actually running with a lower Vcore than normal so everything is good.

However, I do have a question. At normal voltages doesn't Vcore mostly manifest as a problem by pushing up temps? I mean obviosly you don't want to set your Vcore to something rediculous or you will just blow out your CPU. But if you keep it reasonable I thought that any stress to your CPU will show in the CPU temps before anything else.

Thanks in advance.

 

[V3NOM]

I think around 70 C in prime95 is pushing it, but is fine. in real world applications/games you will never see that number, not even in ridiculous multitasking. at 100% load, you will still see about a 10 C drop from your Prime95 temps. I find F@H is a good indicator of temps, but is not always reliable.

prime95/orthos has its place in stress testing, but they do NOT represent real world temperature values.

 

[CompuTronix]

Philosophytutor,

Some useful tips; when discussing test programs, Vcore or temperatures, always be specific and define your terms:

■Vcore? BIOS differs from Idle CPU-Z or Load CPU-Z due to Vdrop and Vdroop, respectively.

■Prime95? Small FFT's is a steady-state 100% workload used for CPU thermal and stability testing, and differs from Blend which is a variable pattern workload used for memory stability testing. The proof is in observing the thermal signatures, which react directly to load. Run each test then watch SpeedFan's "Charts" and see for yourself.

■Temperature? At what Ambient? As you're well aware, CPU differs from Core, so for the benefit of others who are less informed, be certain to maintain the distinction, as they're not interchangeable terms.

And yes, Vcore = Heat.

Once again, enjoy your rig!

V3NOM,

70c? Which one? CPU or Core? Again, these are not not interchangeable terms, so without being specific, the distinction becomes blurred, which contributes to the confusion that so many users find when trying to understand temperatures.

Also, I'm curious whether you noticed the first paragraph in my second post:

Understand that once temperature and stability testing have been completed, there are no games or applications you can run which will approach the steady-state 100% workload of Prime95 Small FFT's.

Incidentally, I salute you for always promoting F@H, which I believe is a very noble endeavor.

Comp

 

[Philosophytutor]

@CompuTronics,
Yes, I should be more specific. Thanks for the advice I only started learning this stuff last week. So I can use all the advice that anyone want to share.

To be more specific -
Results

Tcase = Idle 46 / Load 63
Tjunction = Idle 47 / Load 68

Variables

Ambient = 22
Chipset = 775 LGA
C2D = E6750
CPU Cooler = AVC PENTIUM 4 DUAL CORE HSF Z9H741K001
Frequency = 3.6ghz (up from stock 2.6ghz)
Load = Prime95 (Large in-place large FFTs)
Motherboard = EVGA NFORCE 680I SLI MB REV D
Stepping = Revision G0
Vcore = 1.3875 (Thanks for the Vcore note. I didn’t know that and I will keep a closer eye on it in the future).

As I mention above I was using Prime95s in-place large FFTs, which it says would result in maximum heat. Tonight I will try the small FFTs and see if I get different results.

Thanks again for all the advice and help.

 

[V3NOM]

err he was talking to me i think... "*bold* V3NOM" :lol:

yeah i was saying 70 C on the cores is fine for prime95, but i would not go much further if possible.

 

[randomizer]

On the topic of CPU lifespan, my 8-year-old 800MHz Athlon Thunderbird is only now showing signs of degradation. It used to be Prime95 stable for several hours at 958MHz (I think it was about that) at stock vcore of 1.75V. Increasing voltage made no noticeable stability differences. Recently I noticed that it will fail Prime95 quite quickly unless I drop it down to 936MHz. If you intend to keep your CPU for this long then you may find that you need to adjust your overclock in time, but not for many years if you keep it within specifications as Comp mentioned.

 

[V3NOM]

mmm really depends on the CPU i think though, i mean my RAM was stable at 1T/1N timings for a week then it was ridiculously unstable... dropped it back to 2T/2N timings and all is good.

i think newer cpu's wouldnt have as long a lifespan as those old cpus tbh, but really, who keeps a CPU for that long? i mean for your main machine obviously, after 2 years it won't most likely run games at max, and after 5 it's completely obsolete.

 

[randomizer]

If you swap out the video card it could last 2-3 years. My E6600 is over 2 years old and still kicks butt. I've run it well outside of specifications for short periods too, such that it was about 75C at idle CPUs are quite hardy when treated with "care."