[jmcentee]

I have been task with putting together a cost effective cfd cluster for about £15,000 use a £1=$1 coversion to get the right idea. The cluster is mainly going to be used for starccm+ (unlimited proccessor license) for trialing OpenFOAM, and maybe other CFD software. The cluster may need to be expanded later. The options I am cosidering are.

1.a) DIY built rackmount with Z77 motherboards intel i5 3770K with 16 GB RAM per node. Second hand ebay 20GB infiniband cards, switch and cables. budget with therefore streach to 30 nodes (120 cores).

1.b) same as above but with 10GBase-T ethernet, budget only goes to 17 nodes (68 cores).

2.) A DIY opteron 4 cpu motherboard, 16 cores per cpu, 256 GB RAM per node could streach to 2 nodes (128 cores)

3.) The starcmm+ partner solution. Blade system intel Xeon dual 8 core cpus per node, 48 GB RAM. Also 2 nodes (32 cores)


I currently favour option 1a). Does anyone have any idea of what point a gigabit network is too slow and infiniband is needed, is the number of cores important or number of nodes?

Option 2) I don't like as the AMD opteron chips, although have 16 cores, they only have 8 fpus, I don't know how the software would cope with that,plus when all are heavily used it starts being seriously reduced in speed.

Option 3) is just expensive

Getting new inifiniband kit seems difficult, and very expsenive.

Does anyone have any good reasons why I should not go with option 1?

Thanks

John