Powerbook L3 Cache

lucys_trip

I was just wondering if anyone knows how large the L3 cache is (physical dimensions on the chip), in the Powerbook, how much more expensive it is to have 2MB instead of 1MB, and if there's any disadvantages to having more? If it's not a big deal, size and cost wise, why doesn't Apple utilize a 2MB cache instead of only 1MB? Wouldn't the added cache size make it scream even more?



On a seperate topic, any idea why PC manufacturer's haven't started using L3 cache yet?



Thanks,



LT

barto

Level 3 cache connects directly to the CPU. It costs lots, and doesn't deliever More MHz. Hence, Intel and AMD don't use it.



L3 is a chip off the CPU, and different capacity chips are the same physical size. It's an issue of cost. In a data starved chip like a G4, having the maximum L3 chache, as long as it's reasonably fast, is a must.



Say goodbye to all that with the PowerPC 970.



Barto

ironchef82

What are the performance implications of the 12" PB lacking an L3 cache? Is it serious enough to warrant waiting until the next revision (or saving more money) to get a G4 with an L3 cache? I'm definitely not an expert with this...

icruise

It will slow the machine down a bit when compared to the 867mhz 15" Tibook, but (very) preliminary tests at Barefeats seem to indicate it will be equal to or faster than the previous 800mhz Tibook. Sounds pretty good to me, given the size.

mr. fantastic

The L3 cache makes a big difference!! You can particularly tell between the 800 Powerbook and 800 iMac, which lacks the L3 cache (and is cheaper, too). The overall system is much more responsive. Yeah, it costs a lot more - but at this time, we have no choice considering the huge Mhz gap between Macs and PCs.

kcmac

Bare Feats info.



<a href="http://www.barefeats.com/pb17.html"; target="_blank">http://www.barefeats.com/pb17.html</a>;