Hi,
Quote from: buzzzzz on January 14, 2007, 12:27:12 AM
3.02 p4 with Hyper Threading using only 50% cpu.
I'd just like to point out that a P4 with Hyper Threading is not quite the same as true dual core machine, or one with multiple independent processor chips. When a P4 HT says it's using 50% it's really using much nearer 100%. An HT chip has one full processor and a "virtual" processor. In a somewhat simplified description, this virtual processor works by putting instructions into the gaps between the instructions the full processor is working on. Chips like the P4 often have gaps in their instruction queue or pipeline. The maximum theoretical performance increase you can get with HT is maybe 20%, realistically probably somewhere around 10%, compared to theoretically 100% for a chip with two full processors like a dual core one.
Windows sees the HT chip as two separate processors, even though the bulk of the processing is always being done by the full processor and the virtual processor doesn't contribute nearly so much. Due to this a machine with an HT chip will say it's using 50% CPU when really that means it's using 100% CPU. When TG2 is multithreaded you might get a 10% increase in rendering speed, maybe, whereas a true multiprocessor machine could potentially get a 100% speedup ( though it might realistically be more like 50-60% ).
I need to write a FAQ for this
. I just thought I would mention this to let you know your machine is running much closer to 100% CPU use than 50%. My PC is a 3.0 GHz P4 HT machine too.
Regards,
Jo