[selowitch]

The previous G3 iBook had 512k of L2 cache. Why, I wonder, does the current G4 iBook have only 256k of L2 cache?
One might argue that less L2 cache is necessary with the faster/better processor, but one wonders if Apple is actually downgrading in some categories in order to lower costs. If true, it might signal a disturbing trend in logic board design.
L2 and L3 cache make a big difference in performance, and it's one of the things that really distinguishes the PowerBook line from the iBooks.

[ccsccs7]

Originally posted by selowitch:
The previous G3 iBook had 512k of L2 cache. Why, I wonder, does the current G4 iBook have only 256k of L2 cache?
One might argue that less L2 cache is necessary with the faster/better processor, but one wonders if Apple is actually downgrading in some categories in order to lower costs. If true, it might signal a disturbing trend in logic board design.
L2 and L3 cache make a big difference in performance, and it's one of the things that really distinguishes the PowerBook line from the iBooks.

The did the same thing when the switched from the external 512KB cache to the 256KB on-die cache with the PowerPC G3 CX-based iBook (with FireWire). The on-die cache returned to 512KB with the PowerPC G3 fx-based iBook of May 2002.

The common argument was that by going from half CPU speed with 512KB cache to full CPU speed with on-die 256KB had about the same performance.

G3 512KB to G5 256KB...plus, it keeps the iBook from being as fast as the Powerbook 12", which previously had "only" a 256KB cache.

[dracoleb]

It just has to do with what chip they are using. They are using the same chip that was in the 12"PowerBook Rev.A, at different clock speeds. The Powerbooks got a bump to a newer G4 that has 512k L2 and the iBook got the old model one with 256

[selowitch]

Originally posted by dracoleb:
It just has to do with what chip they are using. They are using the same chip that was in the 12"PowerBook Rev.A, at different clock speeds. The Powerbooks got a bump to a newer G4 that has 512k L2 and the iBook got the old model one with 256

Oh, dear. Does that mean I can fry an egg on the left side directly over the power supply?

[dracoleb]

No, it is much cooler, possibly because of the different casing, or the different HDD. Most of the heat on the left palm-rest comes from the HDD, rather than the processor. Personally my iBook G4 has never been more than slightly warm

[cryon]

yeah I must agree that the new iBook is very cold compared to almost every other laptop i've tried. Good work Apple!