HyperThreading leading to performance degradation

[Doom9]

http://news.zdnet.co.uk/0,39020330,39237341,00.htm
Better get an X2 or Opteron ;)

[charleski]

The critical comment is:Where multiple threads access different parts of memory but are simultaneously processed by the chip's Hyperthreading Technology, the shared cache cannot keep up with their alternate demands and performance falls dramatically,Which is not that surprising.

TBH, I think I see better encoding performance on my 2GHz P4M than my old (533MHz FSB) 3.03GHz P4-HT - probably because of the P4M's larger cache.

[tsp]

Sometimes HT does improve the encoding speed. (http://forum.doom9.org/showthread.php?p=672461#post672461) So as allways meassure the speed with and without HT. Although I'm pretty sure that my next cpu will be a X2 and not a pentium 4 HT.

[Revgen]

@TSP

Street prices (http://www.pricewatch.com/prc.aspx?i=3&a=442067) for 3800+ X2's are starting at about $315 + tax + shipping right now over here. I'm not sure what their price would be in Europe.

They're also supposed to be pretty good overclockers. (http://techreport.com/reviews/2005q3/athlon64-x2-3800/index.x?pg=14) They seem to run stable at 4600+ speeds with good air cooling.

[tsp]

Yes that was exactly the one I will get. The price here for a 3800+ X2 including tax(25%) is ~ $400 and the motherboard I think I will use with it is a ASRock 939NF4G-SATA2 (http://www.anandtech.com/mb/showdoc.aspx?i=2524) for $94 (incl. taxes). The good thing about this motherboard is it has both AGP and PCI-E (In fact both can be used at the same time although not in SLI). But this will have to wait after christmas.

[Revgen]

Sounds good.

I'm a little worried about the motherboard chipset though. It seems to be made by ULi. Usually I see ULi chipsets on cheapie mobo's at computer shows. Anandtech thought it was alright, so hopefully they are right.

[Div_X Factor]

The cheapest 3800+ X2 i can get here is $353 USD so is still a bit much for me :( but i'm running a 3000+ venice core @2305Mhz default vcore with Abit AV8 3rd eye (http://www.rage3d.com/reviews/mobo/abitav8/) so i'm still a pretty happy camper :D

[tsp]

hmm maybe I should get an Opteron 165 instead. It's priced about the same as the X2 3800+ 200MHz but with 2x1 MB cache and seems to overclock well (http://www.hardforum.com/showthread.php?t=974066&highlight=opteron+165+overclock)

[Revgen]

Yeah, but you also need to buy Registered DDR DIMM modules. These cost more than unbuffered DIMM modules.

[tsp]

No need for registret ram because it is a 939 pin opteron. So it should go into any socket 939 that supports a dual core processor.