[Peter Stevens]

Hi All,

Quick query probably for the experts out there. I'm a professional photographer based in London running mainly Photoshop CS2 on my older PowerMac G5 Dual 2GHz with 8 memory slots.

In addition to the measly 256Mb+256Mb DDRAM installed by Apple in slots 1 and 2, I had a further 512Mb+512Mb DDRAM installed in slots 3 and 4 by the vendor, who shall remain nameless at the moment. I've been waiting since then to install further memory and a couple of weeks ago I purchased 4 x 1Gb DDRAM from Crucial. The memory was installed successfully and recognised in the System Profiler - it was installed in slots 5,6,7 and 8. This brought the machine up to 5.5Gb of RAM.

It was only then that I noticed that the both 512Mb chips installed by the vendor were of a different specification - PC2700U-25330 DDR SDRAM as opposed to PC3200 DDR SDRAM.

I haven't had any stability problems at all with the G5, but I'm wondering if this could cause the system to be slower than it should be? Also Photoshop CS2 doesn't recognise the full 5.5Gb of RAM when assigning the %age to be used by Photoshop in its preferences. Running the 'quick' Apple Hardware Test v2.1 does not reveal any problems or errors, but given the huge files this computer regularly batch processes, I want to maximise it's efficiency.

The original purchase date on the invoice was 24/11/2003 and the vendor may not exchange the RAM.

I rarely post here, but read regularly and thanks to anyone who takes the time to reply to this query.

Cheers,

Pete,
London

[flanders]

Pete, I think the RAM should function properly but it might have slowed down the bus to that speed. So, I'm thinking it is slower--but whether you would notice I'm not sure. The general rule for memory buses is they run at the speed of the slowest component and in your G5 you have to pair them on both channels it's probably running all the memory at PC2700. HTH.