Pay attention to IO bandwidth if you’re building a machine with multiple GPUs like this!
In this setup the model is sharded between cards so data must be shuffled through a PCIe 3.0 x16 link which is limited to ~16 GB/s max. For reference that’s an order of magnitude lower than the ~350 GB/s memory bandwidth of the Tesla P40 cards being used.
Author didn’t mention NVLink so I’m presuming it wasn’t used, but I believe these cards would support it.
Building on a budget is really hard. In my experience 5-15 tok/s is a bit too slow for use cases like coding, but I admit once you’ve had a taste of 150 tok/s it’s hard to go back (I’ve been spoiled by RTX 4090 with vLLM).
In this setup the model is sharded between cards so data must be shuffled through a PCIe 3.0 x16 link which is limited to ~16 GB/s max. For reference that’s an order of magnitude lower than the ~350 GB/s memory bandwidth of the Tesla P40 cards being used.
Author didn’t mention NVLink so I’m presuming it wasn’t used, but I believe these cards would support it.
Building on a budget is really hard. In my experience 5-15 tok/s is a bit too slow for use cases like coding, but I admit once you’ve had a taste of 150 tok/s it’s hard to go back (I’ve been spoiled by RTX 4090 with vLLM).