opteron 175 core temp question

[DaveElls]

I had a 3700+ san diego for awhile but decided to jump on the dual core bandwagon. I purchased the opteron 175 and at the moment stock cooling but I had a question. I noticed using a program such as core temp or everest that the cores have ~10C difference in temps, is this normal? One core idles about 28-30C the other idles at ~38-40C. Underload using prime95 it goes up to ~50-52C and ~60-62C. This seems a bit high to me and I'm wondering if I should RMA this processor. I know it's stock cooling but I do plan on overclocking this when I get a better HSF and I'm worried that core is just going to get too hot.

 

[DaveElls]

bump? any ideas?

 

[lopri]

No, it's not normal. Under the specified voltage, the difference should be 2~3C. Does the gap widen as the OC / voltages go up? Or is it steady? It could be many things but my guesses are:

• 1. DTS (digital temp sensor) was placed in a wrong place by AMD. It is supposed to be put on the hottest spot of the core, but it can't always be accurate. In this case, you should go by the higher temp reading of the two. Search for the average temperature of your CPU/OC and if the hotter core is within a reasonable temp of others' reported values, I wouldn't worry too much even if the other core is abnormally cooler.
  2. One of the cores is just inferior. This is more likely a scenario and it's simply that 99.9% of the time the two cores are not equal. Most of the time the gap is 2~5C and the gap tends to widen as Vcore rises. In this case, you should again go by the higher temp reading of the two.
  3. Your HSF and the CPU's IHS aren't making a good contact. Lift up the HSF and check the surface contact.
  4. The CPU core isn't making a good contact to IHS. There is only one solution to this other than RMA'ing the CPU - Remove the IHS and re-apply TIM or just put the HSF on the bare core.

If the difference is 10C as you describe, it's an extreme case of either 1,2,3, and/or 4. I'm afraid the hotter core is a so called "dud"..

 

[lopri]

Try PM'ing the author of CoreTemp. His thread below:

http://forums.anandtech.com/messageview...?catid=28&threadid=1947373&STARTPAGE=1

Hey, wait. Read the following article by the CoreTemp author. I might be mistaken.

In Rev F chips from AMD, the reported temperature also seems to be quite accurate, but from different reports and white papers I've seen, the CPU leaves the factory without having the DTS properly calibrated. AMD claims it could have an accuracy range of ±14ºC. The only thing I've noticed is some older AMD CPUs either have a very large delta between two cores or sometimes give some really low temperature readings. I guess this is understandable as this feature was unofficial in those CPUs.

http://www.overclockers.com/articles1378/

 

[imported_Seer]

Hmm.... my x2 has an internal and external temperature. The internal reading is always much higher, although the gap increases as temps go up. Since the dc opties are functionally similar to the x2s, I would guess that its the same thing.

 

[DaveElls]

Thanks for the responses here, sorry I haven't gotten back sooner. I generally don't really like to OC on stock cooling so I haven't tried that yet to see if the gap widens or not. I've tried reapplying the HSF a few times with no signifigant change, at least not in the gap. though I did bring the overall temp down of the two by 2-3C. I guess I'll play around with it a bit more. The gap doesn't seem to increase under load however, so I'm wondering if it'll stay consistant with OCing as well.

I actually had one other question. I'm mostly used to overclocking SocketA's, I did a bit with my 3700+ but I probably could've pushed it higher. How hot should I let it get? What I often wonder when I see people discussing temps is are they discussing the core temp reading or the old socket temp.


Ah after writing this I did check and it is a revision F, so I guess I can't rely too much on those temp readings.

 

[customcoms]

The stock Opteron cooling is not your typical stock cooling-its is a very very good design, and the only air cooling units that are better are the giant 120mm units (i.e, Zalman 9500, Scythe Infinity, Thermaltake SI-120). Even my 120mm Zalman 7700AlCu is hotter than the 4 heatpipe stock opteron cooler! http://www.gamepc.com/labs/view_content.asp?id=dcopteroncooling&page=8
Based on that review, its not even worth upgrading to a 9500 over the stock cooler-its like a 2 degree delta. Who can argue with free?