Following my post yesterday about the possibility that Speed Fan may be providing me with inaccurate temperatures on my Intel i7-920 I did some quick research last night.
As I had suspected SpeedFan was trying to be too cute … too clever … and falling flat on its face.
It had always maintained that it had detected 8 cores and would tell me the temperature of each core.
I always kind of knew that the i7 didn’t have 8 cores. That is why I talked about ‘virtual’ (or surrogate) cores in yesterday’s post.
What the i7 does, as did quite a few Intel processors going back to c. 2002, is to cleverly exploit multi-threading technology (a.k.a. hyper-threading). Each core tries to maintain (via pipelining, I think) to concurrent execution threads.
But the i7 only has 4 physical cores. Even Intel is adamant about that.
So for SpeedFan to report DIFFERENT temperatures on Core #0 and #1 — is a flight of fancy. No two cores. What we have there are two threads, on separate pipelines, on one core. One core, one temperature. Each thread is not going to have its own temperature.
Yes, I know that SpeedFan, per its name, has more to do with automatically controlling the rate of system fans … than being a temperature probe per se. I wasn’t using it to control my fan speeds. I am cool with having my fans running at the same speed. But, SpeedFan blew its credibility. So it ha to go.
After some research I ended up also downloading and installing Core Temp 0.99.5. I kind of like it. Seems to do what it claims to do. Shows me ambient, low and high temps. on 4 cores — and even shows it, cutely, on my task bar, in four different (customizable) colors. Four cores, four temperatures.
I also looked at other popular utilities like CPU-Z. i7-920 four cores. Not eight.
In my books CREDIBILITY is all. Credibility is the start and the end. SpeedFan lost its creds.
Hope this helps. In case you are wondering the i7 cores, at low load, run around 109-111F.