Hacker News new | ask | show | jobs
by borramakot 2160 days ago
Just to throw in one more complication, I'll assert that the only benefits of FPGAs over ASICs are one time costs and time to market. Those are big benefits, but almost by definition, they aren't as important for workloads that are large scale and stable. So, if you do have a workload that's an excellent match for FPGAs, and if that workload will have lots of long term volume, you should make an ASIC for it.

So, for FPGAs to be the next big thing in HPC, you'd need to find a class of workloads that benefit from the FPGA architecture, for long enough and with high enough volume to be worth the work to move over, and are also unstable or low volume enough that it's not worth making them their own chip.
2 comments
cbzoiav 2160 days ago
Thats not entirely true - the flexibility can have its own value. Unlike an ASIC you can handle multiple workloads or update flows.

For example timing protocols on backbone equipment handling 100-400Gbps. Depending on how its configured you may need to do different things. Additionally you probably don't want to replace 6 figure hardware every generation.

Another example is test equipment where you can't run the tests in parallel. A single piece of hardware can be far more portable / cost effective.

link
borramakot 2160 days ago
I may not have said it well, but I broadly agree with you. If a workload needs high performance but not consistently (e.g. because you're doing serial tests by swapping bitstreams), predictably (e.g. because you need flexibility for network stuff you can't predict at design time), or with enough volume (e.g. costs in the low millions are prohibitive), an ASIC isn't the right solution.

But my point is that for FPGAs to come to prominence as a major computation paradigm, it probably won't be because it outperforms GPU on one really big workload like bitcoin or genetic analysis or something. It'll have to be a moderately large number of medium scale workloads.

link
mindentropy 2159 days ago
There is also glue logic between different interfaces that can be satisfied with FPGAs or CPLDs.
link
Unklejoe 2159 days ago
> I'll assert that the only benefits of FPGAs over ASICs are one time costs and time to market.

There's one more big one: the ability to update the logic in the field.

link