1 mb cache

[Scooby2]

I was browsing the net earlier looking for core2/Am2 info and came across a forum (cannot provide link) where the following subject was under discussion.

That AMD are planning to drop their 1mb cache (per core) x2 range. A comment was made that this was down to the fact that the 1mb cores also contained 3 hypertransport links that would be useable on 4x4.

Can anyone confirm or debunk any of this ?

 

[ltcommander_data]

That AMD are planning to drop their 1mb cache (per core) x2 range. A comment was made that this was down to the fact that the 1mb cores also contained 3 hypertransport links that would be useable on 4x4.

What I can say is that all desktop and server AMD processors that have 1MB L2 cache are identical in die layout. The differences between Opterons and regular A64s are just in microcode programming and optimization, length of validation, and presumably quality of materials. Everything favours the Opterons of course. So it is true that the 1MB A64s and X2s have 3 HT links like the Opterons just that 2 are disabled either physically after manufacture or probably just in the microcode. What AMD is doing by discontinuing 1MB cache processors for consumers is to shift those chips into the server market where the return is higher. This is good for them because it maximizes their profits while their production capacity is constrained. Increased production from Chartered and Fab 36 is supposed to alleviate this.

The interesting thing as you point out is the affect this would have on the 4x4 platform. I've heard that the 512k L2 cache models really do only have 1 physical HT link in order to save transistors. I don't know for sure personally, but I think it's very likely. I always wondered why AMD was so specific about the 4x4 platform being only available to the FX processors and how they would justify that with other 1MB cache processors available that have 3 HT links. Now with the elimination of those models it's doubtful that the 512k X2s will have the HT links necessary to operate in 4x4, which would explain why AMD said it would only work with the 1MB FXs. This should mean that people's dreams of a cheap dual X2 3800+ 35W 4x4 system is unlikely. (The Energy Efficient models also aren't involved in the recent price cuts).

The only hope is that currently both the 512k models and the 1MB models are called the Windsor core whereas previously there were separate names for the 512k and 1MB models. Still it's doubtful that the 512k models would just be reject 1MB parts since there wouldn't be nearly enough volume and it wouldn't be cost effective.

 

[sex_monkey]

im interested in how much difference 1mb l2 cache makes versus 512kb im planning on buying a x2 processor when the price drops come and im thinking the 3800x2 is 100 quid cheaper than the 4400

 

[RichPLS]

I believe the Opty 175 or X2-4400 to be the better chip... 11x multiplier is easy to overclock to 2.64GHz...

 

[borandi]

I see a difference between my X2 4400 and my mates X2 3800 =D
My 4400 is OC'ed (on air) to 2.5Ghz, but the warm weather is testing my patience with temps (55ºC on full load).

 

[ltcommander_data]

As always the answer is to check out THG's Interactive CPU Chart.

http://www23.tomshardware.com/cpu.html?modelx=33&model1=237&chart=69&model2=235

You can look at the results of the X2 3800+ and the X2 4400+ in the types of applications that you run. Those are still the S939s not the DDR2 capable AM2s but the performance difference isn't that much and the relative difference between the two should still be the same.

Overall there isn't a crazy difference between the two and the X2 3800+ is the best value AMD processor, especially after the price cuts. It's really a moot point if you are waiting for those cuts though since by that time, you'd have a hard time finding the X2 4400+. I believe most of the major stores have already delisted the 1MB models. For reference, doubling the cache may provide a performance increase in some cases, but a clock speed increase improves performance in all cases. At least with the discontinuation of the 1MB models, we won't have to answer that question anymore. I'm not discouraging you from asking questions of course since they are valid.

 

[m25]

im interested in how much difference 1mb l2 cache makes versus 512kb im planning on buying a x2 processor when the price drops come and im thinking the 3800x2 is 100 quid cheaper than the 4400

It looks like we'll all run after the 3800+ when prices drop!