> In my floating-point heavy tests on i7 however, there is still a small advantage in leaving HT on, the common wisdom is if you are doing FP, HT is pointless and may actually harm performance, but that doesn't match my observations if your working set doesn't fit into L2 cache. YMMV.
I benchmarked this myself using POV-Ray (which is extremely heavy on floating point) when I first got my i7-3770k (4 cores, 8 threads).
Using two rendering threads was double the speed of one, four was double the speed of two, but eight was only about 15% faster than four.
I don't think I've ever actually seen an example of real-world tasks that get slowed down by HT. Every example I've seen was contrived, built specifically to be slower with HT.
I benchmarked this myself using POV-Ray (which is extremely heavy on floating point) when I first got my i7-3770k (4 cores, 8 threads).
Using two rendering threads was double the speed of one, four was double the speed of two, but eight was only about 15% faster than four.
I don't think I've ever actually seen an example of real-world tasks that get slowed down by HT. Every example I've seen was contrived, built specifically to be slower with HT.