L2 or L3 cache??? really important with audio apps.

[andre tchmil]

Is the L3 cache some much more better than L2 for PT and other applications ?
Can someone explain ?
thanks

[andre tchmil]

c'mon experts!

[mikeoxbig]

this question has been asked a few times before and nobody has had any real answers. i'm beginning to think that it doesn't make a difference. does anyone relly know?

[img]images/icons/mad.gif[/img]

[beatboy]

I would say that it would help in any app that needs to have algorithms handdled as quick as possible. L2 & L3 let the cpu have short & qiuck paths to hold the results of registers.

[Lee Blaske]

The common wisdom is that it would help if you want to use a lot of native plug-ins. In the case of ProTools, RTAS plug-ins.

Lee Blaske

[Allan Speers]

So where does one find a level 3 cache? Is that in the new DDR-ram Macs?

[beatboy]

L2 & L3 are on the chip.

[crow]

there is a thread going on in the "LE" section right now about this:

http://duc.digidesign.com/cgi-bin/ub...;f=24;t=014257

someone answered your question in great detail

[dcornutt]

Addendum:

Originally on the first G4..the L2..was a "backside" cache..off chip..with it's own bus direct to cpu.

Later revisions of the G4..moved the L2 "on chip" running at full cpu speed (although some models vary)...and added L3 as backside cache..off chip..with ti's own bus.

What your looking for in cache..is the "speed"..more so than the size.

IN an L2, L3 setup...where L2 is on chip..it carries more registers..and one register is reserved to pass on instructions to the L3.
. At this point..the L3 and L2 can communicate with each other directly...however...you have to look at 2 things.
One is..the speed at which this communciation takes place...the other is..that these additional registers add latency to the whole thing compared to just an on chip L2.

In that regard..it's etirely possible..for a fast L2...of sufficient size...to be more efficient than a L2 , L3 setup...IF the L2 and L3..setup is communicating at much lower speed ratio.

All this varies...model to model, chip to chip...Mother board..to motherboard and even with the same chip design...with varying mhz.

The 2nd thing to note is..that this different architecture of passing on instructions..and communication of L2 to L3..can be leveraged in the "programming" of the "software" as well.

According to some sources...OS 9 cannot fully utilize the L3 as OS X can. They expect the advantages of the L3..chip to chip..should be more apparanent in OS X..than in OS 9.