Yeah, it is funny you should ask!
I was seriously contemplating Chirpa's offer.. but
I have two tests..
for i in 1 2 3 4 5 6 7 8 ; md5sum /dev/zero & done
This just generates cpu load.. a specific type of cpu load, but load none the less
The other test is multiple compiles of the linux kernel
Anyway, with the 8 copies of md5sum running I hit an overheat problem..
According to frontview -> system -> health, temp2 reached 61 degress C.. which is 1 over the CPU limit.. I tried patching the vpd file bumping it up to 65 (same as temp1) but it doesn't seem to get it's limits from the vpd info file in /proc....
Having a look in /sys for temp info I found that:
grep . `find /sys -name temp?_*`
Now, these values are the values reported by the processor itself (one per core).. The max value is 85 degress C.. but I'm still not sure what "max" means.. According to the kernel doc:
temp1_max - All cooling devices should be turned on (on Core2).
So, does that mean the CPU will be damaged if it is exceeded.. or does it just mean that the CPU fan must be running flat out if the CPU is this hot?
The reason I ask is that temp1_crit also exists.. and says 100 degrees C.
So.. with the E6700, the temp2 reading was 1 degree over the limit (I think this limit is imposed by Netgear) and the core's reported a temperature of 89 degrees C.. Hot hot hot..
I've whacked the E6600 back in:
Now, the temp1 is still higher than the "max" value.. I still don't know if that is a problem.. however. temp2 on frontview reports a MUCH healthier 53 degrees C
So.. the E6600 is 8 degrees cooler running flat out.. and is below the 60 degree limit.. both CPU cores report higher than max levels.. but both are lower than the "crit" level.. so I'm still working out (reading the source and CPU spec) what this means.
Slight pain is that the CPU cooler is attached with screws.. the backing plate is part of the case so heatsinks that screw on can be used.. Stock intel coolers, for example, with their push plugs cannot be used in this case.
If only the case was 1 CM wider a MUCH nicer fan could be put in..but from what I can tell, the tallest cooler you could use is 53mm and the selection is limited..
From what I can tell, the NAS is happy and relatively cool running an E6600, but an E6700 is going to be pushing it.. I've not tried a kernel compile reliability test or a memtest on the E6700 but I don't honestly think the CPU cooler is up to it..
If I can get a larger cooler, that uses screws rather than push plugs, I might try again.. but in the mean time 2.4Gig seems that safe limit with the stock readynas cooler.. (which is remarkably small compared to the intel stock ones! like less than half the height!)
Shame.. Still 2.4G is pretty damn good!
If I find out what the temp1_max actually means (ie can it be safely exceeded / temp1_crit is the REAL top limit) I'll let you all know