AM-2 procs to be slower?

[Sazar]

http://anandtech.com/weblog/default.aspx?bid=279

Back in January we got our hands on a shiny new Socket-AM2 motherboard and a Socket-AM2 Athlon 64 4800+. I didn't pay too much attention to the fact that the 4800+ AM2 chip we had was a 2.4GHz/1MB part, just like the Socket-939 variant, I was too busy being happy about having an AM2 platform.

Needless to say my excitement vanished after I ran the first performance numbers and it offered about half the memory bandwidth of an average Socket-939 platform. Remember that the major change with AM2 is the migration to DDR2-667 (and DDR2-800) over DDR-400, so memory bandwidth should go up - not be cut in half.

I chalked it up to being an early board with an early CPU, but honestly I had no idea whether it was the motherboard or CPU that was at fault here. Usually when I get my hands on a chip from Intel < 6 months before its release, its performance is pretty close to final. I had Prescott about that amount of time before its release and its performance didn't change. With AMD CPUs it's a little more difficult since they're equipped with an on-die memory controller; so what used to be easy to trace back to the motherboard could now be either the board or the CPU at fault.

I checked with AMD's partners and they were seeing the same poor results that I was, and I also checked with AMD, to see if they had seen anything different. Of course AMD's response was that they were seeing better performance than I was. I figured that AMD wasn't going to launch AM2 6 months later and cut performance in half, so I held off on publishing any numbers. AMD isn't the only company to receive this sort of treatment - I actually did the same thing with Prescott when I first tested it. I figured I had an early version of the CPU since performance was actually lower than an identically clocked Northwood; of course the outcome of that situation was much different as Intel actually did reduce performance with Prescott

Could the AM-2 platform be AMD's prescott?

I sure hope not but this does not augur well at a time when Intel is showing that it has stepped up its own challenge and has presented a very viable option.

It seems odd that there would be memory issues but then again, remember AMD delayed the A-64's initially due to mem controller issues. The mem controller is on-die therefore it is not as easy to switch things around as, say, a north-bridge on an intel board.

I wonder if there could be a work-around, like a hybrid nb chip to alleviate some of the performance over-head incurred?

Logically, this would not make sense since it simply introduces extra latencies into the entire process, but if it would help bridge the performance delta that anand is seeing, it might be a pragmatic short-term solution.

Here's to hoping AMD keep their heads on straight and keep their performance level high.

 

[kcnychief]

Too early to tell atm I would assume, but makes me feel a little better that I didn't hold out for that before upgrading.

My new AMD 4400+ kicks booty!