since that I have SMP I would never want to go back to Uni again, when I had that Dual P3/EB 1Ghz, I used it mostly for Quake3 @ 1600 x 1200 x 32 with my good ole GF3 at max detail FSAA x4S and AF x8, with 2 P3/EB CPU's I hit the 70 frames per sec with 1 CPU I only hit the 37 frames per sec., there fore SMP was alot better, I also found out when I was playing Flanker 2.0 and FS 2000 and 2002 this system pwned them with ease, because of Dual CPU.
After this system I had the Dual AthlonMP 2200+ with a Hercules 9700 Pro, it was meant for FS 2002 most of the time and Quake 3 buut then with the possibillity of FSAA x6 and AF x16 looked lots better, tried FS 2004 on it was way to slow on max detail and density though, ran it on normal details , it was time for something bigger.
So After the Dual AthlonMP 2200+, I sold that and went for a Dual opteronDP 244 setup with ATi's newest X800XT PE VPU based graphics accelerator.
I did a little test with it in FS 2004, but then at max density and max detail
Flight Simulator 2004 works with 1 CPU about 60% faster, I've tested that on my Dual OpteronDP 244, the whole world is in 3D, that cost's lots of CPU power, ram is also a great of importance, for the 3D special effects I use the ASUS ATi X800XT PE Deluxe, only got 1GB of ram, gonna fit another 1x TwinX Corsair XMS Platinum 2x 1GB PC 3200 Low Latency ECC Reg, so I have a total of 3072MB aka 3GB of ram, to fly on reso 1600 x 1200 x 32 at max detail and max density with FSAA x6 T3[ FSAA x18 ] and AF x16 with a playable frame rate of 53 frames per sec, and an Athlon64 3200 + S754 the one I had before the Dual OpteronDP 244 was way too slow, i tried the same settings it only got like 23 frames per sec.
It's also because that the OpteronDP CPU 3 Hyper Transport links has and a dual OpteronDP has then 6 in use, an Athlon64/64 FX has on 1 in use and a X2 has 2, thanx to AMD's Hyper Transport technology, thier CPU's don't need so much Mhz to keep up with others, the more HyperTransport links the lesser Mhz/Ghz they need to keep up.
That's where the OpteronDP comes in to place, in FS 2004 I have 6 Hyper Transport links in use, with my A643200+ the one I sold a short time ago, only had 1, it ran at 2Ghz and had 1MB of L2, yes it was a Clawhammer., my 2 OpteronDP 244's run at just 1.8Ghz per CPU and also have 1MB of L2 but also have each 3 Hyper Transport Links, atotal of 6 in use, in 3D mark 2001SE my Dual Opteron Sys scores 22216 points with the X800XT PE, an Athlon64FX 57 with a GeForce 7800GTX in SLI scores about the same 22218, only 2 points more, the FX 57 runs at 2.8Ghz but it suffers because it only has 1 hyper transport link, my dual Opterons have 3 each it easily keeps up with the fastest FX cpu with the newest GFX set, unbelievable, but true.
here's my proof, click to enlarge:

here's my url of it:
http://service.futuremark.com/compare?2k1=8461253just a default bench at 1024 x 768 x 32 all settings at default under Win2K Pro + SP4 and Omega Catalyst 2.6.0.5a Omega 5.1
well sorry for the big post, but might as well post everything hehe I was well on my way, this is the reason I use only SMP based systems, even the Pentium4 with Hyper threading has it's advantages, but real SMP is alot better.