MTVU on Q9550: Slowdown or no effect at all

[Nova eXelon]

Hi,

a friend of mine has an old Q9550 and he wanted to re-play Xenosaga again.

So I set up PCSX2 for him and was suprised by the strange behavior the MTVU option showed. It goes like this:

In a situation where he already has like 70fps (limiter off), than turning MTVU on boosts the FPS to something like 120.
But if he is right under 60 (55 or so) turning MTVU on lets im fall even lower to ~40.

In Rule of Rose shortly after the beginning in front of the gate PCSX2 falls to 45fps. Turning MTVU on doesn't change anything. If we go away from the gate the FPS go up to 60 again (68 with limiter off). Turning MTVU now on and the FPS are jumping to 110 or so. Leaving MTVU on and going back to the gate, the FPS are falling again to 45.

I tried different SVN's including the one I currently use (5517) and the official 1.0.0. It's the same in all of them.
Completely different from the experience with my PC so far.

So is there some advanced "thing" one should turn off in BIOS or something?

His complete specs are
Q9550 CPU @ Stock 2.83GHz
GA-EP45-UD3 Mainboard
4GB DDR2 RAM 1066MHz

Thanks in advance

[miseru99]

It's not strange - completely normal, MTvu is a hack and needs alot of cpu power and architecture speed just to synchronize the new thread, that power loss is different depending on game and cpu architecture, in some games and especially on older/weaker architecture, MTvu will result in a slowdown or will give no difference at all, nothing you can do about it, except upgrading. Even on fastest cpu's MTvu results in higher overall cpu usage soo yeah it's a great hack which will speedup loads of games and not cause much problems in others, but surely not something to turn on and forget it's existence(hence it's an optional hack not a hardcoded feature;]).

[Nova eXelon]

So its really just that the Q9550 is too old from an architecture point of view?

Thats sad.........

But thanks anyway