Real Temp - New temp program for Intel Core processors

[unclewebb]

AndrewZorn: I found this test kind of interesting on my Q6600 - G0:



Run Prime95 small FFTs and for "Number or torture test threads to run:" enter 3 instead of 4.

When your CPU is only at 75% load, it constantly moves that load around and it seems to be based on the data coming from the digital thermal sensors. I think when a process asks to run on any core then the CPU runs it on the core that is reporting that it is running the coolest. There are two Dual Cores within a Quad so I think the load is first split in half (more or less) and then those two loads are shared by core0 / core1 and by core2 / core3.

When uncorrected, my core2 always reports the highest Distance to TjMax value which means it is running the coolest so in this test it gets the biggest load and its partner, core3, gets to take it easy. The sensors on core0 / core1 always report very similar values so their half of the load is shared much more equally between those two cores. In both situations, the Distance to TjMax is being balanced for both sets of cores. In theory, Core i7 should be able to move the work load around and balance the temps between all 4 cores at the same time but the design of the Core 2 Duo seems to prevent this.

Task sharing by the CPU seems to be directly based on data from these temperature sensors. When you have a core reporting that it is running cool, it is going to get a bigger share of the work load. If in fact it tends to run at the same temperature as its partner but is misreporting its status, then it's going to be forced to run a bigger load which will make it run a little hotter than its partner. You can tell by looking at the graph that this balancing is going on constantly. Sensors that are not well balanced from the factory can lead to individual cores running at slightly different temperatures.

At higher temperatures where these sensors are much more accurate, the effect of the above declines and you will typically see core0 / core1 running at the exact same temperature and core2 / core3 also running at the exact same temperature. In most of the Q6600 screen shots I've seen, it's almost always core0 / core1 that report that they are running hotter. Typically about 0C to 5C which is shown in the above screen shot.

This might be just a sensor issue but it doesn't seem to be. Think about what would happen if during manufacturing that there was a slight difference between how the IHS contacted each set of cores within a Quad. It's possible that two of the cores might be making better contact with the IHS than the other two so the heat transfer is more efficient and they end up running cooler. Go try my test on your Quad and see what you get.

radaja: Your temps are great when running at that speed.