[Stankutiwa]

Can a 1.6 mac pro motherboard be replaced by the dual core motherboard regardless of the costs involved.I would like to keep my casing and possibly slot in a faster motherboard with it's processors?

[Waragainstsleep]

Most of the time you need the processors (with heat sinks) to match. There are one or two exceptions but its been so long I forget.
You may find you need a matching power supply too. And don't use parts from a dual core to upgrade your 1.6 either.

[BLAZE_MkIV]

at this point your probably best off buying and entire G5 and swapping the guts wholesale.

[reader50]

Title fixed, removing the "mac pro" part. The MacPro started at 2.0 GHz, so 1.6 GHz single core makes it a PowerMac G5.

[ChrisF]

You'd need to replace everything inside except for the disks. Power supply, processor(s), video card, RAM are all different. It's absolutely cost ineffective, if you can get all the parts. The newer board may not even fit without replacing parts of the case.

[BLAZE_MkIV]

I though there was something cosmetic about the case that was to be maintained.

[Waragainstsleep]

I'm not entirely certain which units use which power supplies. There is a 450W and a 600W. Yours will certainly use the 450W. I imagine you could go to a single 1.8 without changing it out but it seems likely that any dual CPU board will use so much more juice that it would need the 600W. Having said that the 600 seems to cover all the way up to the dual 2.7GHz which will use a damn sight more power than a dual 2.0 as its running at its limit and is water cooled.

You probably don't want to change the PSU as its one of the worse parts you can change in any Apple machine ever. Less hassle if you do the board etc at the same time I guess. I hated changing those too.

[chipchen]

Long story short, not worth it.. time or money.