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x4 955 BE Hot and Loud?

That says nothing about them having core sensors :confused:

AMD chips are rated by their tCase max temperatures... as far as I'm aware the "core" temperatures that are reported by software like everest and coretemp are not actual measurements but calculated from the single tCase reading...which is why sometimes they make no sense (coretemp shows my cores as cooler than the tCase temp which is impossible).
 
gurusan said:
(coretemp shows my cores as cooler than the tCase temp which is impossible).
Click to expand...
yes i had this with my 720 and they said its a faulty sensor.

but with my 965 the core temp are higher then the tcase temp.

as i said maybe they was just telling me crap info...
 
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The point I was making is that there is only 1 sensor present on the entire chip so you obviously can't get different readings for coretemp and case temp. So the coretemps will be just guesstimates that are calculated by the software.
 
Dancer said:
Is there any way to test the sensor? I've fitted an intake fan to the front ventilation grill of the case now. Will get the temps when I reboot (writing this from my wife's new x2 550 which is silent, cool and fast... maybe I shouldn't have bothered with x4)
Click to expand...

Sorry if you have said, but what case are you using? The fact you didnt have one installed is a bit worrying! What is the size of the rear exhaust fan? What are your ambient temps? And do you have a PSU that assists in cooling?

Sounds like a case issue to me
 
Gundog48 said:
Sorry if you have said, but what case are you using? The fact you didnt have one installed is a bit worrying! What is the size of the rear exhaust fan? What are your ambient temps? And do you have a PSU that assists in cooling?

Sounds like a case issue to me
Click to expand...

Blue Storm II 500W, which indeed has a "120mm fan with variable thermal sensing control" and I can feel it blowing hot air out the back.

I have a fairly old, but roomy and sturdy aluminium case. I've never used case fans before as it just never had any problems with it, but I did have my CPU fan mounted to blow air straight out the rear ventilation grid. There are two ventilation holes at the rear and two at the front (although one is covered by the drive bays). As of yesterday I have mounted an 80mm akasa fan to suck in air from the front to ensure it takes in cool air and pushes it out the back. I might get one for the back too.

I'll see if I can take a picture tonight.
 
Ok, I've now applied mx-3 thermal paste and there is a total of two case fans (80mm, akasa). I'm quite impressed with the cool air sucked in by the frontal fan, but disappointed by the rear fan which doesn't seem to be moving much air at all (they are different types of akasa fans and the rear one rotates slower.

I've increased the voltage back to full power, but temps still go to 62c when running prime95 with the case open. Good news is that they don't go much beyond 62c in 35 or so minutes (once to 63, but frequently dropping down to 60) so seems to max out there. I've not tried running prime95 with case closed as my idle and crysis tests shows temps are around +15c with case closed. Disappointing, so suggestions to improve things welcome.

First time I ran prime95 one core failed after 5 minutes which is a bit worrying (see screens below). Didn't have round-off checking enabled, so enabled that and re-ran prime95 with no other change and it ran for over half-an-hour without fail. I realise I should test longer but didn't have time yet. Is it possible the first fail was a fluke? Anything I can do (reading stress.txt it seems a core failing like that is bad...)?

prime95opencasetest_corefailsafterf.png


prime95opencasetest_overhalfanhour.png


Besides the one core failing, is 60-62c while running prime95 expected/acceptable? Kind of rules out overclocking doesn't it.
 
error like that could mean ram or cpu-nb issue..

uselly u can tell if the core clock is unstable or ram or cpu-nb issue..

if i get a error like that could mean ram or cpu-nb issue, if i get a blue screen its core clock is unstable

but every system is different..
 
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I've decided to split off getting my case cooler into a new thread, so I can concentrate on CPU/heatsink/prime95 here.

To see a picture of my case and me talking about case airflow go here.
 
955BE's memory controller ("Northbridge") is inside the CPU, you therefore have two CPU voltages that need to be kept stable when overclocking these are CPU Voltage and CPU-NB Voltage..

Simply put to keep a stable overclock on a 955BE you need a balance of:

1. CPU Frequency - Kept stable by CPU Voltage
2. Northbridge Frequency (the communication between the CPUNB/MB/RAM) - Kept stable by CPU-NB Voltage, and to some extent NB Voltage at high CPUNB Clocks
3. Correct 'Relationship' between the CPU and CPUNB Frequency (typically CPUNB Frequency is CPU Frequency - 1200, i.e. 3200mhz CPU Frequency = 2000mhz NB Frequency)
4. RAM Stability
 
modez said:
I was able to successfully undervolt my 955 C2 at 3.4GHz to 1.28V stable , hope this helps.
Click to expand...

Firstly and most importantly why did you need to undervolt it in the first place?

I see from this jpegs that your cores are running around 35c in idle(?). That is actually quite a bit hotter than mine with case open, but about what I'm getting with case closed.

What sort of temps do you get when running prime95 (or some other cpu intensive process)?

When I undervolted the machine was stable for gaming, but cores would frequently fail when running prime95, so are you sure it is fully stable, or just for your use?
 
Dancer said:
Firstly and most importantly why did you need to undervolt it in the first place?

I see from this jpegs that your cores are running around 35c in idle(?). That is actually quite a bit hotter than mine with case open, but about what I'm getting with case closed.

What sort of temps do you get when running prime95 (or some other cpu intensive process)?

When I undervolted the machine was stable for gaming, but cores would frequently fail when running prime95, so are you sure it is fully stable, or just for your use?
Click to expand...

Undervolting Phenom II 955.

http://www.techpowerup.com/forums/showthread.php?t=101049
 
That thread is pretty pointless tbh as it's on the premise that the clock will be a 24/7 clock.

With tools like phenommsrtweaker and k10stat you can customize your idle voltage and clock and only knock it up to your higher clock/voltage when you want it to. I keep my chip @ 1.5GHz and .896V until I game or need some more power, then knock it up to 4GHz 1.488V
 
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gurusan said:
That thread is pretty pointless tbh as it's on the premise that the clock will be a 24/7 clock.

With tools like phenommsrtweaker and k10stat you can customize your idle voltage and clock and only knock it up to your higher clock/voltage when you want it to. I keep my chip @ 1.5GHz and .896V until I game or need some more power, then knock it up to 4GHz 1.488V
Click to expand...

Indeed its quite nice how you can have multiple profiles on difference CPU usage
 
modez said:
Undervolting Phenom II 955.

http://www.techpowerup.com/forums/showthread.php?t=101049
Click to expand...

In the last few days I've learned a lot and yes your post about undervolting did help as it got me considering the voltage (again).

The stock voltage on auto provided by my motherboard (Gigabyte GA-MA770T-UD3 MA770) is 1.4v and after lots of reading I realised that this is rather high even if below the 1.5v max for the cpu. Apart from your undervolt people were reporting default stock voltages of 1.35 and doing overclocks on that voltage too. I initially tried CPU Voltage of 1.3v and reducing CPU NB VID by -0.5v, but that caused instability on some cores in prime95 and I had one freeze which might have been related.

I've now settled on 1.35v and kept the CPU NB vid on standard voltage and it appears to be stable and is much cooler (less than 30c on idle).

Even better I now have one 120mm fan on each side of my CPU cooler in a push and pull configuration, and I've mounted two 80mm fans pulling air into the case (across the HDs) from the front vastly improving case airflow. Temps are now more or less the same with the case open or closed, but I'm giving the thermal paste a few days to settle before I try prime95 for any time. It never went above 46c playing crysis which is good. :cool:

Conclusion: Don't be afraid to use a lower voltage than suggested by your mobo, even if overclocking.
 
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