If I had an Athlon running at 1.6GHz (not OC'd) or so, and I upgraded to a board running an Athlon 64 running at a comparable speed (also not OC'd) , would I notice any difference? (Assuming I used the same RAM type and amount, of course).

Probably the biggest benefit of the A64 is not the fact that it's 64-bit, it's the fact that the memory controller is built into the CPU...that alone makes it better/faster than any Athlon XP

http://www.pantherproducts.co.uk/Product%20Reviews/Athlon64.shtml

Asus A7N8X-X
1800+ @8x210mhz
512mb PC3200
Ti4200/8X 128mb
WDC 60GB

Interesting. I might give this another thought.

Now, do all of them have this? Or just the more expensive ones, or just the FX series?

all the A64 lines have it

A64 3000+
MSI K8T-Neo FIS2R
ST 1GB DDR433
Ati Radeon X800 Pro
250GB SATA HDD

I have seen this at least 5 times over the years with new hardware. Resist the urge to be the first kid on your block to have the latest and greatest. Wait until much of the software out there has been converted to use the full 64 bit benefit,and you will find that the prices have dropped substantially and the power has increased substantially. Guaranteed. I see the prices beginning to drop on the lower-end models already. The best is yet to come.

Give a man a fish and you feed him for a day;
Teach a man to fish and you feed him for a lifetime;
Then industry pollutes the water and kills all the fish.

If your going to get a 64bit series, then I would reccommend just save up for the FX. You'll definitly see improvments.

groups.yahoo.com/group/simplycomputers2

if you want it! buy it!!!!!!.....

I stand outside of my system, looking in...and smile and smile and smile

My question would be, what are you going to be doing that requires 64-bit processing? Unless you're running a 64-bit OS and using 64-bit applications, there's not going to be any real benefit.

I agree with ranchand, having upgraded to clawhammer chip and asus k8 rather than an fx (& the difference in price between a barton 3200 and the 'hammer' was negligble )
the performace difference was well worth it, tho an fx would be supremely better the fx price just isnt yet.
im not intending to run 64 bit apps just wanted more bang for my bucks and got it.
and the k8 ? well asus released a new bios that suppports the 3700 64 & sempron line so the mobo will get extended life after all.
i try and stay 6 -8 months behind new developments, its the old marketing trick 'early adopters of technology ' always pay top dollar, wait a bit get it half price, the enjoyments the same.
It all depends on how deep your pocket goes.
http://www.penstarsys.com/reviews/tech/amd/a64_k8v/
Im betting by xmas gt6800 graphics will drop in price by then the market will have realised not many ppl will spend 350 on a card for one game (D3) so they will drop also,
anyway this time next year its all out of date , like prince corum says....
;D