Try running Prime95 with an AM of 14, 3 threads, HT off, HT on...Sorry, but I am in the office on an older XP P4, HT is not available, and it is certainly not multicore... !Andrew

Sorry guys but should you not be flying the bird instead of disgussing HT? It has not any effect on FSX what so ever/Michael Moe

I did some tests:HT OFFAM=14 (1110)Frames, Time (ms), Min, Max, Avg 9670, 300000, 22, 39, 32.233 HT ONAM=255 (11 11 11 11) Frames, Time (ms), Min, Max, Avg 6974, 300000, 11, 32, 23.247 Two threads running in each core. Terrible result as expectedAM=170 (10 10 10 10) Frames, Time (ms), Min, Max, Avg 9153, 300000, 20, 38, 30.510 One thread per core. Massive improvementAM=168 (10 10 10 00) Frames, Time (ms), Min, Max, Avg 9699, 300000, 23, 40, 32.330 Same as before but leaving Core #0 alone. Equivalent to AM=14 HT off. Even better results than AM=170, matches the AM=14 / HT off baseline test resultsAM=84 (01 01 01 00) Frames, Time (ms), Min, Max, Avg 9501, 300000, 22, 39, 31.670 Same as AM=168 but using the second virtual core for each true core instead of the first. Basically the same result, which ilustrates 10 10 10 10 is for the most part same thing as 01 01 01 01 (all cores are virtual)Of course temps where consistently higher (5-10ºC) in all HT on runs. You can maximize performance with AM=168 or AM=84 if you need to have HT enabled for other applications, but will never get better performance than with HT offAt least that's what I see here, feel free to use whatever settings you think work best for you, but I doubt anyone will ever convince me that HT helps at all

Interesting results there. It really does look as though HT has negative effects if any on FSX. I will only play with an affinity mask to take off from the initial core, to see if there is any improvement given the info concerning fibres. Thanks for looking into these specifically. I would say you have shown fairly unequivocally that HT is not good for FSX. Andrew

HT OFFAM=14 (1110)Frames, Time (ms), Min, Max, Avg9670, 300000, 22, 39, 32.233 HT ONAM=84 (01 01 01 00)Frames, Time (ms), Min, Max, Avg9501, 300000, 22, 39, 31.670 I would say for an i7 2600 core, this is quite the same.Ok, maybe the temp, will be a little higher with HT on, but then againwhen using other games such as BF3, as I do, I will benefit having HT on./ Leffe

Thanks Andrew.One more thing. Playing with ******* Altuve's online tweaking tool, it suggests an affinity mask of 84 for a quad core + HT, confirming the above results.Moreover, for a 6 core CPU + HT it suggests 1344 (10 10 10 00 00 00) and the same hexa core without HT, 56 (111000)Uses only 3 cores for a 6 core processor, so I guess 14 would work too for a 6 core CPU HT off (001110)

HT OFFAM=14 (1110)Frames, Time (ms), Min, Max, Avg9670, 300000, 22, 39, 32.233 HT ONAM=84 (01 01 01 00)Frames, Time (ms), Min, Max, Avg9501, 300000, 22, 39, 31.670 I would say for an i7 2600 core, this is quite the same.Ok, maybe the temp, will be a little higher with HT on, but then againwhen using other games such as BF3, as I do, I will benefit having HT on./ Leffe

Absolutely Leffe :)I never said that HT would hinder performance in every case. You just need the right affinity maskAll I'm saying is HT will never give you better performance than HT off + AM=14. The same at best

So for HT On with i7 930 the AF should be ? I have it set to 252 at the moment.

So for HT On with i7 930 the AF should be ? I have it set to 252 at the moment.

Is HT enabled? if it is then try 168 or 84If it's disabled, then 14Please let us know how it goes. I've seen people in the past who seemed to prefer 252 for some reason

Is HT enabled? if it is then try 168 or 84If it's disabled, then 14Please let us know how it goes. I've seen people in the past who seemed to prefer 252 for some reason

I've set AM=84 and there appears to be a notable improvement on FPS and core temps are down a bit to below 60. Seems smoother. I'll see what 168 does.