Emulator

It looks like it shows factory clock of your CPU. For example i got i5 2500k running at 4GHz and in dolphin it shows factory 3.3GHz.

Works fine with an i7-920 (4 cores, 8 threads) so it's not directly linked to HT.

Can someone reproduce this issue? Also, on which OS was this bug happening?

Windows 7 Ultimate x64...

I did some tests.

C2D E5300 @ 2100MHz, 9800GT, 4GB of ram
vs
i3 2310m @ 2100MHz, GT540m, 4GB of ram
all graphical settings were set to lowest and game was run at native resolution to avoid any gpu bottleneck!

Resident Evil Archives (remake)

Single core mode - sandy wins, 5-15 fps advantage (as expected)
Dual core mode - core2 wins, 1-3 fps advantage (???)

Is it possible that dolphin uses two threads from a single core in dual core mode when using i3 cpu?
I don't think there are any problems with older i3 mobile cpus, i ran the same game some time ago, and as far as i remember performance was very good and there were no any core/thread problems.

I also see this, I've got an i5-750 and it says:
8 Cores, 2 logical threads per physical core
And that HTT is supported

The i5-750 is a quadcore, with no hyperthreading.

Also win7 x64 sp1

@vojin: It is widely known that Hyperthreading has no real value and should ALWAYS be turned off, particularly for emulation.

I, for one, can vouch to this issue.

Dolphin r7461 x64 (Dolphin main site buildbot)
Windows 7 Home Premium x64
Core i3 540 @ Stock
Hyperthreading DISABLED (which makes this all the more strange)

Thank you. However, i can't turn off Hyperthreading on my laptop, options in bios are very, very limited.

I disagree with you about HT. Dolphin can't use more than two cores, so HT makes no difference, but there are certainly some cases where HT can be useful.

Very wrong core detection on my Dell XPS 15z with i7-2640M. It's dual core with 4 logical threads, but Dolphin says 4 cores with 8 logical threads, and will only use 50% CPU in dual core mode (25% in single core mode).

Same here, have an Intel Core i3 2100 ( 2 Cores with Hyperthreading )
I get aprox 30% more FPS by deactivating Hyperthreading in the BIOS. And it stutters no more in the games ...

But its really annoying to switch allways the BIOS-Setting, because i need it for some other apps. Looking forward for a patch / workaround. :)

Is this ticket at process? I mean, theres no update since December 2011 ( Status: OnHold ). It's really annoying. Please update to more priority.

No. The only way you have to make this issue more high-priority is by submitting a working patch.

Intel Core i5 3570k, dolphin-emu 3.0-801 detects HT (8 cores) while it isn't supported.
Games speed is 100% but CPU loads only 50% per core or less (top shows cpu loading ~170-190%).

Any update???

We do, performance is terrible on dual core CPUs with hyperthreading. It's probably using threads from the same core. Enable/disable Dual Core option in Dolphin makes no difference in performance.

@ vojin.djekic
Dolphin appears to only use the "number of cores" value when LTtC or OpenMP are enabled. (two features which some of us want removed anyways)
(Dolphin's knowledge of the number of cores is not as important as you seem to think.)

It also appears that Dolphin is unable to use the second core when running on dual core cpu with HT. Basic stuff isn't working, don't care about LTtC or OpenMP right now.

bravo

I can confirm this is happening. I get the issue in 3.0 and 3.5 64 bit. I am using Win 7 x64 SP1 on an i5-2500K (which has no HyperThreading). Link to the screenie here:
http://s3.postimage.org/3xwyu8zir/Untitled.png

I would be happy to give any more details needed.
Adding more***

I do not mess with OpenMP and do not know what LTtC is so I cannot speak for those :)

Awesome. Thanks!

This still needs to be fixed instead of just hiding the core count from the OSD, especially if OpenMP is getting it's core count wrong.

@ white.phoenix
OpenMP gets the count elsewhere now.