Even with the Windows Media Encoder 9 x64 (with 4 isolated threads now) a Pentium D EE (2 cores, each HyperThreaded) has far higher value, and similar performance when encoding video than my AMD Opteron 270 (2 CPUs, each with 2cores).
I would go with the Pentium D or Pentium D EE for video encoding.
Grab Windows Media Encoder x64 Edition 9 Series if you plan to run Windows XP x64 (be it via AMD64 or Intel EM64T) from:
http://www.microsoft.com/windows/windowsmedia/9series/encoder/default.aspx ; too. If you've got 4 CPUs (virtual or otherwise, such as Pentium-D EE) you'll benefit heaps.
I'll recommend an AMD Athlon64 X2 / Opteron (dual-core) series when they give the best performance, and / or best value.... but in this case the Pentium D EE (now that 4 thread versions of encoders are showing up) comes so close to an Opteron 270 at half the price, if not outperforms it... Then it doesn't justify doubling your cost to get roughly the same performance.
If a CODEC or application runs in 2-4 'isolated' threads heavy in SSE2(+) then it will benefit from an Intel (dual-core, hyperthreaded, or both) CPU dramatically. AMD does have very good SSE2(+) performance in single isolated threads (or 2 isolated threads on the Athlon64 X2), but for Video Encoding they don't hold a candle (price : performance wise) to the Pentium D / D EE.
Summary:
You're after high MFLOPS (SSE2) here, but not high MIPS..... the Intel option gives high MFLOPS (SSE2) at a lower cost if (and only if) the application / codec runs in 2 (or more) isolated threads..... and pretty much all of them do for Video Encoding, it was the first major market they (Intel) targeted the technology at.
Contact Info available at:
http://users.on.net/~darkpeace
If you like I'll let you RealVNC (Remote Desktop) connect to my PC and watch (but not use keyboard / mouse) me encode a 1 hour video, check Task Manager, CPU load out, etc on my Opteron 270. I'm in a GMT+10 (AEST) time zone though, but the weekend (Sat Midnight) starts here in 1 hour : 10 min apx from the time I've made this last edit..
Remeber I've got the AMD Opteron 270 'option', but I am offering to let you see first hand (via remote) why I recommend the Intel for Video Encoding.
At least that way you can put any doubts to rest. Esp on 2-pass encoding jobs... [
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