I just shut down my lone 32 bit linux machine (P4). Everything left is Mac or Windows (and a PS3). I am considering converting one of my Athlon 64 X2 windows machines to Linux. I'm trying to sort out the pros and cons, and if so, 32 or 64 bit.
Funny, I'm going the other way... shutting down my WinXP 32b crunchers and converting them to Xubuntu 64b.
Linux 32 bit: Can add WEP-M+2 Project, but lose out on DepSpid, Spinhenge, PrimeGrid, uFluids, Proteins, and Nano-Hive. Not very attractive.
I don't run WEP-M, DepSpid or PrimeGrid. Proteins and Nano have no work. Spinhenge is a loss but not one of my "biggies".
Linux 64 bit: Lose the same Windows-only projects above. But you can still run many/most 32 bit linux projects using the anonymous platform, but some are just not available.
Starting with boinc v5.8.x and some version of the server code projects should send 32b app when no 64b app is available automajically. The only one I see that this does not appear to work on is SDG.
Here's what I've got running today on Xubuntu 7.10 (Gutsy) 64b:
Proven to work now
(with IA32 and stdc++ v5 added):
ABC (64bit integer math based, should run substantially faster with 64b OS/BOINC/APP)
Assume to be working, need new WU to test:
APS (64bit integer math based, should run substantially faster with 64b OS/BOINC/APP)
Not expected to work (either only Windows or Linux in beta testing):
Spinhenge (linux in beta)
SZTAKI (SDG, 32bit Linux only, confirmed, server upgrade needed?)
Here's the big question in my mind. Of the native 64-bit projects (below), do any of them provide a significant performance improvement? I know ABC does. Do any of the others? And how much?
I've read ABC runs up to 92% faster / same credits. Claims are that APS has same app based on 64bit integer math and should see same. Haven't run ABC 64b long enough to prove this out yet.
Other than that what I've read is roughly what Dotsch said. But I think those numbers are based on Linux 32b to 64b and Win 32b to 64b. Not win 32b to Linux 64b which is what what most of my ongoing conversions are.