Question about my G4 processor cache...

might have something to do with the version of processor cards. I too asked many on ebay and others on here that same question. My G4 DP 1.25 card has the complete 4MB L3 cache - 2MB per processor, however I have seen mostly on the FW800 machines the 1MB/processor L3 cache.

I was also told that the earlier Mirror Drive Door machines which I don't have, though 1.25 dual was introduced with those had 2MB L3 Cache per processor, the 1ghz dual processor also had 2MB, while the 867 dual did not.

Although, I don't have the FW800(glad I don't, since a lot on here are complaining about overheating problems) DO have 1MB L3 cache. The copyright date on my G4 8570 MDD machine is 2003 - which leaves me to believe its a 2003 mirror drive doors machine, but with a revised logic board.

I believe you own one MDD model and one FW 800 model. The fastest MDD processor was dual 1.25 Ghz, and those shipped with 2 MB level 3 cache. But the FW 800 offered a dual 1.42 Ghz processor with 2 MB level 3 cache and a 1.25 Ghz processor with 1 MB level 3 cache.

So to answer your question, they aren't the same machine.

Nadav- did you buy your machine used? It sounds more like you have a MDD machine with a FW 800 processor card in it.

hmm.. nope, try again. After hearing all those overheating problems with that guy from Brazil using a FW800 MDD, I would never put myself to that level. No, I got this MDD in pretine condition. The specs are as follows: Its a dual 1.25 with the 2MB L3 Cache(total of 4MB L3 cache), and I just got the copper heatsink to replace the one I originally had.. I find at this point its not worth me to get the 1.42 processor card, since 10-13 percent is really miniscule at best., unless someone has a 1.42 processor for less than 100.00, then I'd take it, but its not worth it since I get plenty of power(impressive power) with the dual 1.25. My original G4 was a digital audio 733 w/1MB L3 cache. I am passing this one onto my son who is 8 years old - a great computer still, although I plan to upgrade his processor on that.

I still would like to know why the later 1.25's were L3 cached down to 1MB instead of 2MB?

Oh I was confused by your first post...I thought you said you didn't have the firewire 800 port but you did have the 1 MB L3 cache. My mistake.

Well the FW 800 is superior to the MDD... it has firewire 800 obviously, offers faster processing power and more stock graphics cards. That's really it, they are basically the same machine. The MDD was released August 2002, then replaced by the FW 800 January 2003 only for that to be replaced by a re-release of the MDD in June of 2003. Why did they do that? I'm not sure. It seems like a downgrade.

By the way why do you think you have a revised logic board?

Well if you bought it used, it looks like someone took out the FW 800 logic board and put a MDD logic board in and put a custom piece on the back to close up the existing hole. The FW 800 had two firewire 400 ports and one firewire 800 port. The firewire 800 port is a little different looking. Here's a pic, you can see the 800 port below the two 400 ports. If that is what your's looks like, then you have a FW 800 G4, minus the FW 800. Bummer.

http://www.s155158671.websitehome.co.uk/Resources/FW800-New-fan-Position.jpg

Yeah you could put it back in, but honestly I don't think it's worth it unless you have a need for highspeed firewire devices. Firewire 800 runs at 800 Mbits/sec, which is roughly 66 MB/sec (most people don't recognize the difference between megabits and megabytes - just divide by 12). That's pretty fast for periphreals, but it depends on how often you use them, and whether you want to spend the money. Brand new, these logic boards can be very expensive, hundreds of dollars. You can probably find one used on ebay for cheaper, but they're still a little pricey. Here I just found one-

http://cgi.ebay.com/Logic-Board-Motherboard-Apple-Power-Mac-G4-MDD-FW800_W0QQite mZ200183110867QQihZ010QQcategoryZ25439QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

still over $100. It depends on whether it's really worth it to you. Personally, I would pass and spend my money elsewhere.

The only way to get your cache up to 2 MB is to buy a new processor card. Cache is built in on the card, this is why it makes such a significant difference. Unfortunately, the cards with 2 MB level 3 cache are not cheap. I bought my dual 1.4 for $400. You could try to get an original Apple processor card for cheaper than an upgrade, but they may be harder to find. I looked on ebay and couldn't find one with level 3 cache. Your best bet is just buying a processor upgrade from a 3rd party vendor like Sonnet or Gigadesigns. Other than that, there is no way to increase your cache.