New Laptops: No L3 cache. Mobile Video Editing?

Posted:
in Current Mac Hardware edited January 2014
hi,

noticed the new powerbooks have a 512k L2 cache and faster processor but the new crop eliminated the 1MB L3 cache found on the previous AI powerbooks.



What does this mean for mobile video editors using FCP 4 on powerbooks? anyone notice any difference?



i know encoding uses L3 cache but not sure about FCP4 editing and rendering.



cheers

Comments

  • Reply 1 of 14
    Take a look at Thinksecret



    Apple responds to lack of L3 cache
  • Reply 2 of 14
    Look here. They don't test FCP but in every test they did, the new PB's seem faster then the old ones.
  • Reply 3 of 14
    powerdocpowerdoc Posts: 8,123member
    At least my old 17 inch have something that the new model don't have.

    However, the mobile radeon 9600 is a great improvement over the previous geoforce mx 440.
  • Reply 4 of 14
    yevgenyyevgeny Posts: 1,148member
    The larger L2 cache will prvide a good speed boost over the much larger (and much slower) L3 cache. Also, the L2 cache is cheaper. Don't panic! The new machines are great deals and you can buy one in full confidence that it will work well.
  • Reply 5 of 14
    Quote:

    Originally posted by Yevgeny

    The larger L2 cache will prvide a good speed boost over the much larger (and much slower) L3 cache. Also, the L2 cache is cheaper. Don't panic! The new machines are great deals and you can buy one in full confidence that it will work well.



    for the price of the powerbooks we shouldn't have to be concerned about cost to apple to include L3 cache







    the fact is, they'd be a lot more powerful IF apple did include L3 cache.
  • Reply 6 of 14
    A-men... those thingies are expensive enough to justify "ace" components. Why not put 1MB of L2 cache in then if it's cheaper?
  • Reply 7 of 14
    It's hard to understand why they didn't keep the L3 in there. Was it cost-cutting or engineering? You'd think they would have been able to since presumably the 7457 is smaller and cooler than the 7455 that it replaced.

  • Reply 8 of 14
    Quote:

    Originally posted by Pandoering

    A-men... those thingies are expensive enough to justify "ace" components. Why not put 1MB of L2 cache in then if it's cheaper?



    The chip itself limits the amount of L2 to 512. But I think that the 7457 is capable of taking even more L3, if I remember correctly - maybe 2MB or even 4? And IBM's soon-to-be released new G3 (750GX) will reportedly have 1MB of L2.
  • Reply 9 of 14
    pscatespscates Posts: 5,847member
    I wonder if the next versions of these models (Rev. C of the 12" and 17" and Rev. B of the 15") will have L3 cache? That would mean a chip change, right (7447 > 7457)?



    In any case, I'm sure with the faster G4 (250MHz more on the 15"), the doubled L2 cache and the 9600, it's a more-than-capable machine.
  • Reply 10 of 14
    The new PowerBooks are using the 7447 processor, not the 7457. Maybe this is the reason there is no L3 cache?
  • Reply 11 of 14
    thttht Posts: 3,151member
    Quote:

    Originally posted by Pandoering

    A-men... those thingies are expensive enough to justify "ace" components. Why not put 1MB of L2 cache in then if it's cheaper?



    1 MB? It should be 2 MB at least. Actually, iBooks should get a G4 as well, and could be differentiated to Powerbooks through the lack of backside L3 cache and lowered clocked buses, actually less "ace" components all around. A 1 GHz Powerbook G4 could be 20% faster than a 1 GHz iBook G4 this way. At least in some things.
  • Reply 12 of 14
    amorphamorph Posts: 7,112member
    Quote:

    Originally posted by applenut

    the fact is, they'd be a lot more powerful IF apple did include L3 cache.



    For definitions of "a lot" that approach 3-5%, tops, under normal usage.



    L2 is faster and lower latency, and the new 'Books also have faster system busses. Between those two things, and with size and weight already going up (in the 15") and battery life going down, why bother with 1 or 2MB of hot, expensive cache when you've already got a chip that runs better without it than the last one did with it? And, as a bonus, you get to use a smaller, cheaper and cooler CPU.



    Of course there's a tradeoff - there always is - but in this case it seems to me to be worth it. Apple even passed the savings along in the price cuts.



    As for the 7457's support for L3 cache: It supports up to 2MB of L3, like the 7455, but it introduces a feature that allows it to treat L3 as main RAM, in which case it will support up to 4MB over that bus. This is obviously only a feature of interest in the embedded space.
  • Reply 13 of 14
    The 47 doesn't support L3.



    It could very well be that the 57s are not available yet, and that Moto only managed to get the 47s out the door.
  • Reply 14 of 14
    brussellbrussell Posts: 9,812member
    Quote:

    Originally posted by PBG4 Dude

    The new PowerBooks are using the 7447 processor, not the 7457. Maybe this is the reason there is no L3 cache?



    Yes, but I'm guessing that it was the other way around: Apple decided not to use L3, and so they decided to just use the 7447. I find it doubtful that Motorola had the 7447 ready but not the 7457. But who knows.
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