Let me explain my findings,,,
Ive built and upgraded my socket 478 for over five years now to keep with the latest games at reasonable framerates on the best settings avaliable.
current system, chaintek apogee intel 865 pg 800mhz fsb mobo with sata I controllers and 4gb max ddr 400mhz support. Board is five years old now with 2005 award bios revision 5. Intel p4 3.0ghz 1mb cache 800mhz fsb with ht, purchased from ebay three weeks ago for a pittance to replace older p4 2.8 512k, cooled with Zalman Flower for s478, Socket A boards.. 2gb, 4x512 matched ddr400 2,2,2,5. 1x samsumg spinpoint 250 gb hdd sata II 1 x wd 500gb 16mbche sataII 1 x lacie 250gb external firewire for critical os backups. Sapphire 1950pro 8x agp 512 mb card with zalman flower cooler installed. 650w jeantec arctic modular psu. creative Xf-I Xtreme Audio and wintv tuning card all in luxurious Jeantec Gaming Case. Driving 22 inch 1600x1050 tft widescreen.
Now the point is, over five years ive replaced the processor twice from origional 2.53 quad pumped to 3.0ghz p4 ht with sse3, (Prescott) for roughly £39.00 in total ( E-Bay Rocks, always look for parts posted in incorrect categories, not many people do which is why the bargains are to be had, be vigilant, be patient), Graphics several times, only two new cards, 6800 and 1950 pro, for £210 minus sale of 6800, Harddrives for £ 150 minus sales of older ide drives also read for future use, memory replaced once for £80 minus sales of older memory, new psu for future use £65, creative sound for future use, £35.00 and case for lifetime of ATX £ 55.00.
So for about £500 in parts over 5 years not destined for new 32nm intel upgrade path which i will sit quite happy to wait for on my current system, ive been able to keep up with all the current modern games at great settings on big screen----- untill now!!!!!!!!!!!!
My honest opinion, modern games need fast CPU'S the AI is just too immense on the games I like, ESP rts games, even the AI on games such as Colin MCrae dirt and NFS Pro Street need fast Dual Core.
Overclocking my p4 3.0 to well in the region of 3.7ghz by dropping mem speed in bios to 366, volting p4 to 1.415v and slamming 0.30V on V-Dimms makes these games just playable, Crysis runs ok on my machine now at mixed med and high settings, (Shadows always on med) at native 1600 x 1050 with between 20 and 30 fps, sometimes stuttering at 15 fps in later icy regions. COD 4 plays good as well with above 30fps in almost all situations on native res and high settings and 2x AA 16 Anistropic filtering.
3dmark 05 9600 3dmark 06 5900 superpi 1m 31sec
My sapphire 1950 pro card rocks like stink, have always loved nvidia ( gf4mx440, ti4200, 5200fx, 5700fx, 6800gt) but this ati offering is sublime for price i got it at back over 1 1/2 year ago. I have gpu up to 641mhz and mem at 1600 mhz (800ddr) constantly in 3d, but this with catalyst 8.1, all 7.x do not allow mem to clock on sapphire card. Now at this I know that the 1950 is bottlenecked not by agp8x but by the processor, no person in their right mind would upgrade to 3850 over 1950 with similar high spec 3-5 year old agp system as the peformance increase would be minimal for money spent, even more so with lesser processors than 3.oghz p4 prescot or athlon 64 clocked to 2.6ghz true clock speed. Only socket 939 X2 or Dual core agp, pcie x8 boards with good components should even consider 3850 agp as worthy stopgap upgrade. I know my rig is at the end of its shelf life but am happy to say that the upgrade path I have chosen for 5 yrs has paid off and I have the money in the Kitty now for the onset of 32nm processors 2009. I know that choice will give me another 3-5 yrs upgrade for minimal cost.
Anyone looking to get dx10.1 support on vista is having a bleeding laugh, You what, let me say again, it will not work on older agp systems, I REPEAT>>> You will not get playable framerates on any good modern dx10 game at all. Vista is rubbish in anycase, have vista ultimate and dual boot between 2x winXP (1 gaming os, 1 Work os) 1 linux (Ubuntu) and Vista. XP is and will remain to be the choice OS for gamers the world over untill GPU'S power rocket ships and microsoft really put good dx10 into their games not just press release pics (NEone for Flight Sim X Acceleration please LOL). Ultimately, even super fast dual/quad core silly clocked to 1000bil ghz 1600mhz or greater mem ,radeon 3870, nvidia 8800gt, gts, gtx, ultra, sli, crossfire, sli3way, and the upcoming doubtfull crossfirex can meek out good framerates on the few dx10 titles avaliable, so what hope is there for a pc that cant really keep up with modern dx9 games at decent frame and settings, (Ever played oblivian on med/med low settings, what is the point, (Thank God for 1950 pro, let me go right to the end with hdr enabled)
Final Thoughts about 3850, save your money unless for owners of x2 , dual core agp boards, saying that, if the price is right at launch and you have good spec 478 board but nvidia 6800 or less agp card, could see u through another years gaming, esp on all those 2005, 2006 games you would love so much to crank right up, just forget any AI intensive modern games like Dirt, pro street, world in conflict.