Does Northwood's 512KB L2 Cache run at full CPU speed?

[Charles]

Or it runs at half speed?

 

[AndyHui]

Full speed. It's on-die.

Intel L2 caches have been running at full speed for a while now, and last ran at 1/2 speed with the Katmai.

 

[Charles]

<< Full speed. It's on-die. Intel L2 caches have been running at full speed for a while now, and last ran at 1/2 speed with the Katmai. >>

Tualatin 512KB L2 cache runs at half speed, right?

 

[AndyHui]

Nope...that's full speed as well.

Pentium III Coppermine, Tualatin, Cascades, Dixon
Pentium 4 Willamette, Northwood....they are all full speed.

 

[jeffrey]

When Intel went from half-speed cache to full-speed on the Coppermine they transitioned to a 256-bit path to the 256kb L2 Cache. Anyone heard of the P4's 512kb L2 cache having an increased path as well?

 

[AndyHui]

Both the Willamette and Northwood processors feature a 256-bit wide path to the cache.

 

[Adul]

ATFaq man strikes again.

 

[Charles]

I read an article somewhere before, and I guess it's incorrect information.

 

[imgod2u]

Well, seeing hows moving from the original 512KB off-die half-speed cache to 256KB on-die full speed cache brought a significant improvement in performance, it wouldn't make much sense to go back to that. One thing about Northwood that bothers me, what about the SMT capability that (from what I hear) is already part of the P4 design? Is it finally enabled and if not, why is it there in the first place?

 

[Charles]

When can we start seing Athlon with 512KB L2 cache?

 

[AGodspeed]

When can we start seing Athlon with 512KB L2 cache?

Possibly when AMD releases their next new Athlon processor, dubbed "Thoroughbred". It's supposed to be an Athlon XP shrunk to .13 micron. But that's about it as far as specs for Thoroughbred goes, I don't think anyone really knows whether T-bred will have a 512KB L2 cache.

 

[AndyHui]

SMT is not enabled on the Northwood. It will be enabled on the Prestonia processor.

I guess it would be easier to design something in the first place and then enable it later as needed instead of having to go back and redesign things. It was the Pentium Pro team that designed the Willamette Pentium 4. Considering how far the PPro based designs went, I'm not at all surprised that the P4 designers had a few hidden tricks up their sleeve.

Having said that, I am also interested to see if AMD have anything up their sleeve to extend the K7 design before Hammer comes in.

 

[imgod2u]

Seeing hows AMD is hasn't been around that long, and most of their processor design was based on an already existing x86 architecture, but rather, was simply meant to do the same thing, but better, I doubt they really put anything that hasn't already been used in their current design. I think they're focusing on Hammer right now since it is the first major thing they've done on their own instead of following in Intel's footsteps technology-wise.

Anyway, if Northwood doesn't have SMT enabled, when is Prestonia suppose to come out? Is it yet another remake of the P4 or will it be something else? Any rumors?

 

[Accord99]

<< Anyway, if Northwood doesn't have SMT enabled, when is Prestonia suppose to come out? Is it yet another remake of the P4 or will it be something else? Any rumors? >>



It's available for purchase and works with the existing Xeon motherboards. Here's one guy with dual 1.8

http://www.whiningdog.net/reviews/PC/Prestonia18XEON/18Prestonia.htm