Microsoft Windows Media Encoder Benchmark Results from Tom's Hardware
Coupon codes available on eBay for $1-2
courtesy fatshu
Athlon 64 3700+ Retail (search A0558334) $254 - 25% = $190 [PriceSearch]
Athlon 64 3200+ Retail (search A0558337) $166 - 25% = $124 [PriceSearch]
Athlon 64 X2 3800+ Dual Core (search A0558333) $322 - 25% = $241 [PriceSearch]
Athlon 64 X2 4400+ Dual Core (search A0558328) $500 - 25% = $375 [PriceSearch]
Athlon 64 X2 4800+ Dual Core (search A0558336) $687 - 25% = $515 [PriceSearch]
The Athlon X2 3800+ appears to be able to hit 2.4 to 2.7GHz, so with a little luck your 2.0Ghz 3800+ will equate to a 2.64GHz 5000+
REVIEW 1 and REVIEW 2
^^^Correct, except the L2 is still 512Kx2 instead of 1MBx2. Also, 2.6Ghz would equate to FX-60 speeds 
COUPONS ARE STILL VALID AS OF 1.10 PM (Jan 25th, 2006)