[SOLVED] Is a Core 2 Extreme supposed to run this hot?

The Tiger

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Aug 30, 2013
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I have an old PC with a knockoff LGA775 G41 mainboard and 4GB DDR3. The board only supports 1066MHz. Used to use Core 2 Duo CPU with no problems.

Recently, I got a used Core 2 Extreme QX6850 3.00 GHz processor from Aliexpress for $25. The processor works like a charm but the idle temps of all cores are 53 -55 ℃. During processor intensive tasks the temps hover above 70℃. Prime 95 gets it to 80℃. It doesn't go much beyond the low 80s.


I am not over clocking and the voltages and multipliers are at stock. Even downclocking the processor doesn't get temperature down by much. I use Arctic Silver 5 and reapplied it. Still no change.

I am using this HSF from my old CPU
https://www.newegg.com/product/13C-000X-00281

My old core2 duo E7500 never went beyond 55℃ under full load with this HSF.

Is the Core 2 Extreme supposed to run this hot? Is it damaged from extensive use before I bought it used off Aliexpress? Or do I need a fancy HSF with heatpipes?

My cabinet is a full ATX with 2 fans and a 450W corsair PSU.

Screenshot-20190706-073706.png
 
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92mm fans. It's 130-140w cooler. It'll be better for idle temps, as long as you have sufficient airflow in the case, but won't do all that much for high load temps like stress tests as it's basically a 1:1 ratio still. So your cpu will still be able to max out Tjunction temps, throttle, shutdown etc. Larger capacity coolers have more headroom, the temp curve is lower, so even at full loads, the temps don't get to max. There's a difference between efficiency and capacity.

Tjunction for that cpu is 64.5°C. Anything around or above that temp is in throttle area.

Hope that cheap cooler works, and I'm wrong, but I'm not going to hold my breath.

King_V

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Your E7500 is a Core 2 Duo, 2.93Mhz, with 2 cores, and is on the 45nm process. It has a TDP rating of 65W.

The QX6850 is a Core 2 Extreme with a slightly higher speed of 3.0Ghz, but 4 cores rather than 2. Further, it's on the 65nm process. It's rated at 130W TDP.

So, yes, twice as much thermal output if all cores are pushed. The 65nm vs 45nm means a given core is likely to be hotter/require more power at the same speed, twice as many cores, if all are active, obviously produce more heat, and ultimately, Intel explicitly rating what the TDP is to give guidance for cooling is another giveaway in the puzzle.

https://en.wikipedia.org/wiki/List_of_Intel_Core_2_microprocessors
 
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Karadjgne

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You cannot over-cool a cpu. You could put the biggest cooler possible on that cpu, just means it'll run very quiet, all the time as the fan won't spin fast because it doesn't need to.

You can however under-cool a cpu. It's very easy, you did it without knowing. You took a 95w cooler on a 65w cpu, and stuck it on a 130w cpu. Not knowing that TDP is just power used average at base clock speeds on all cores, not turbo speeds on all threads. Cpu cooler should be 1.5 to 2x the TDP. With that cpu, 1.5 is appropriate since it's 4c/4t, no hyperthreading.

You should be looking at coolers in the 180-200w range minimum. That's 6-8 heatpipes...
https://m.aliexpress.com/item/32814...d=5704amp-ZUQA3Aq8nfZwhMVXv5i03g1562381925415

(scroll way down) you'll want the one that looks just like the picture, most likely also $65
 
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The Tiger

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I would rather go with the two pipe design since I can actually find reviews for it (Antec A30, IF that's a legit listing).

Thank you!! Yes, it has got great reviews but some reviews also state that their processors didn't see over 5℃ decrease from stock. The best thing is it's branded and I will get it in 3 days from Amazon.

But the 4 heatspipe one in Aliexpress looks fancy and also got lots of reviews. Do you think the quality of heatpipes matter or the number?
 

The Tiger

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Aug 30, 2013
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You cannot over-cool a cpu. You could put the biggest cooler possible on that cpu, just means it'll run very quiet, all the time as the fan won't spin fast because it doesn't need to.

You can however under-cool a cpu. It's very easy, you did it without knowing. You took a 95w cooler on a 65w cpu, and stuck it on a 130w cpu. Not knowing that TDP is just power used average at base clock speeds on all cores, not turbo speeds on all threads. Cpu cooler should be 1.5 to 2x the TDP. With that cpu, 1.5 is appropriate since it's 4c/4t, no hyperthreading.

You should be looking at coolers in the 180-200w range minimum. That's 6-8 heatpipes...
https://m.aliexpress.com/item/32814...d=5704amp-ZUQA3Aq8nfZwhMVXv5i03g1562381925415

(scroll way down) you'll want the one that looks just like the picture, most likely also $65

Thanks a lot for your valuable input. You are right. We can't overcool a CPU. Yeah, I should have given more thought to those TDPs. But I had to go for a cheaper one because $65 is really out of my budget to protect a $25 CPU. Got the Antec A30. It doesn't mention TDP on the site. But hope it will do better than the stock, right? I'm not going to overclock.

Just because it has more pipes doesn't necessarily mean it's better. Build quality means something too. I'd rather trust the item for which I can find outside reviews.

Sold!! 😁 Will tell you when it comes.

Screenshot-20190706-085719.png
 
May 4, 2019
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1
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You cannot over-cool a cpu. You could put the biggest cooler possible on that cpu, just means it'll run very quiet, all the time as the fan won't spin fast because it doesn't need to.

You can however under-cool a cpu. It's very easy, you did it without knowing. You took a 95w cooler on a 65w cpu, and stuck it on a 130w cpu. Not knowing that TDP is just power used average at base clock speeds on all cores, not turbo speeds on all threads. Cpu cooler should be 1.5 to 2x the TDP. With that cpu, 1.5 is appropriate since it's 4c/4t, no hyperthreading.

You should be looking at coolers in the 180-200w range minimum. That's 6-8 heatpipes...
https://m.aliexpress.com/item/32814...d=5704amp-ZUQA3Aq8nfZwhMVXv5i03g1562381925415

(scroll way down) you'll want the one that looks just like the picture, most likely also $65
im just going to let you know this is possible you need to get it under -70c thought is not eazy dry ice will do it and iv seen janky water coling setups that involve dry ice
 

Karadjgne

Titan
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92mm fans. It's 130-140w cooler. It'll be better for idle temps, as long as you have sufficient airflow in the case, but won't do all that much for high load temps like stress tests as it's basically a 1:1 ratio still. So your cpu will still be able to max out Tjunction temps, throttle, shutdown etc. Larger capacity coolers have more headroom, the temp curve is lower, so even at full loads, the temps don't get to max. There's a difference between efficiency and capacity.

Tjunction for that cpu is 64.5°C. Anything around or above that temp is in throttle area.

Hope that cheap cooler works, and I'm wrong, but I'm not going to hold my breath.
 
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