3 ms·

I wonder if something like this could be the start of a decent key-value appliance. Hardware designed to perform the role of memcached on the network or similar

I wonder if something like this could be the start of a decent key-value appliance. Hardware designed to perform the role of memcached on the network or similar.

noahl 13y ago
Hmm. At first I thought this would be a waste, because you couldn't use all of its fast compute capabilities on doing key-value lookups. But these things also have much, much more memory bandwidth than regular CPUs (I can't remember if it's 10x or 100x, but that ballpark), and that might work well for these applications. But I don't know how the GPU's memory caching infrastructure works. If the bandwidth is only for serial reads, that could be a problem.
- wmf 13y ago
  K1 has about the same memory bandwidth as every other mobile SoC, which is to say not all that much. Don't compare it to discrete GPUs.
  - fidotron 13y ago
    True, but in my experience if you can avoid hitting the memory the amount of computation you can do per thing is absolutely terrifying. The main thing I had in mind here was hashing for bloom filters. i.e. do the different algos in parallel on a GPU, then pass those values for the main lookup to be done by the CPU.
jjoonathan 13y ago
Like Content-addressable memory (CAM)? I've heard routers have used the stuff to do fast table lookups since forever, but I don't know if anyone has tried implementing a data cache with it. http://en.wikipedia.org/wiki/Content-addressable_memory http://en.wikipedia.org/wiki/Content-addressable_memory
MertsA 13y ago
If you wanted raw memcached performance there was an awesome paper on using an FPGA tied to 24GBs of regular DDR3 RAM and a 10G ethernet port. The result was a memcached server with 3.5 to 4.5 microsecond response time, capable of saturating the 10G port even with tiny key-value pairs, and 13 million requests per second while using 50W of power to do so. http://0b4af6cdc2f0c5998459-c0245c5c937c5dedcca3f1764ecc9b2f.r43.cf2.rackcdn.com/11566-hotcloud13-blott.pdf http://0b4af6cdc2f0c5998459-c0245c5c937c5dedcca3f1764ecc9b2f...

I wonder if something like this could be the start of a decent key-value appliance. Hardware designed to perform the role of memcached on the network or similar.

noahl 13y ago

Hmm. At first I thought this would be a waste, because you couldn't use all of its fast compute capabilities on doing key-value lookups. But these things also have much, much more memory bandwidth than regular CPUs (I can't remember if it's 10x or 100x, but that ballpark), and that might work well for these applications. But I don't know how the GPU's memory caching infrastructure works. If the bandwidth is only for serial reads, that could be a problem.

wmf 13y ago
K1 has about the same memory bandwidth as every other mobile SoC, which is to say not all that much. Don't compare it to discrete GPUs.
- fidotron 13y ago
  True, but in my experience if you can avoid hitting the memory the amount of computation you can do per thing is absolutely terrifying. The main thing I had in mind here was hashing for bloom filters. i.e. do the different algos in parallel on a GPU, then pass those values for the main lookup to be done by the CPU.

jjoonathan 13y ago

Like Content-addressable memory (CAM)? I've heard routers have used the stuff to do fast table lookups since forever, but I don't know if anyone has tried implementing a data cache with it. http://en.wikipedia.org/wiki/Content-addressable_memory http://en.wikipedia.org/wiki/Content-addressable_memory

MertsA 13y ago

If you wanted raw memcached performance there was an awesome paper on using an FPGA tied to 24GBs of regular DDR3 RAM and a 10G ethernet port. The result was a memcached server with 3.5 to 4.5 microsecond response time, capable of saturating the 10G port even with tiny key-value pairs, and 13 million requests per second while using 50W of power to do so. http://0b4af6cdc2f0c5998459-c0245c5c937c5dedcca3f1764ecc9b2f.r43.cf2.rackcdn.com/11566-hotcloud13-blott.pdf http://0b4af6cdc2f0c5998459-c0245c5c937c5dedcca3f1764ecc9b2f...