AM2+ vs AM3 CPUs-- why the 10C increase in max temps allowable before processor damage?

[soccerballtux]

I don't understand what could have changed. Intel's processors are rated for 71 and 73C for quad/dual. Why were the AM3's rated at 71/73C Dual&Tri/Quad when on the AM2+'s overclockers were limited to 63C?

What could have changed? I'm wondering if higher management said "no we have to meet Intel's thermal specs for this, too, so that people can overclock further"

I was limited at 3.4 if I had to stay under 63C.

 

[Fox5]

Probably because the memory controller requires less power when operating on DDR3, so it can handle higher temps at higher clock speeds.
Older phenoms/opterons were rated at around 70C, but only the lower speed ones. Seems like there's a limitation with temperature and clock speed. That might not even be the temp for processor damage, but rather just a failure to operate correctly.

 

[thilanliyan]

Originally posted by: soccerballtux
What could have changed? I'm wondering if higher management said "no we have to meet Intel's thermal specs for this, too, so that people can overclock further"

I think you're reading too much into this. Lol it wasn't a conspiracy holding you back from OCing before. Different chips have different limits but I think keeping at around 60C is a good limit anyway.

 

[taltamir]

i would not go over 60C either

 

[Rhoxed]

125W chips are 61C max and 95W chips are 73C max (as stated by amd +/- a C or 2)

i wonder though, if i change my 720BE to quad wouldnt that make it a 125W chip instead of 95W and wouldnt that now mean i have 10C less to work with?

 

[soccerballtux]

Hm where have you seen this? I thought it was 63C AM2+, 73/71C AM3?

 

[Rhoxed]

Originally posted by: soccerballtux
Hm where have you seen this? I thought it was 63C AM2+, 73/71C AM3?

http://products.amd.com/en-na/...&f6=&f7=&f8=&f9=&f10=&


check the info on the processors

125W = 62C
95W = 71C
65W = 70C

it doesnt matter if it is AM2, AM2+ or AM3, it all depends on the Watts

 

[deimos3428]

Originally posted by: Rhoxed
i wonder though, if i change my 720BE to quad wouldnt that make it a 125W chip instead of 95W and wouldnt that now mean i have 10C less to work with?

Good question. I suppose there are two ways to look at it.
If you unlocked the fourth core on an X3 720 (95W/73C), you'd have approximately an X4 920 (125W/62C) suggesting you'd lose a whopping 11C of headroom. That seems unlikely.

Unlocking an X3 710 (95W/73C) --> X4 910 (95W/71C) suggests you'd only lose about 2C of headroom, as they are both within the same TDP. So while I suspect that the real answer is somewhat higher, you might be wise to use the 62C value to be safe.

Note also that the X4 920 has a maximum voltage of 1.5V, which is 75 mV higher than the nearly identical X4 910 at 1.425V. This suggests that the maximum voltage stated is based on the TDP envelope more than an actual limitation of the chip.

 

[soccerballtux]

Well I've got a decent cooler; not too worried about it. That said, my rig hard reset last night encoding. It was ~64C.