Re: Hardware recommendations to scale to silly load

Shridhar Daithankar wrote:
>> Be careful here, we've seen that with the P4 Xeon's that are
>>hyper-threaded and a system that has very high disk I/O causes the
>>system to be sluggish and slow. But after disabling the hyper-threading
>>itself, our system flew..
>
> Anybody has opteron working? Hows' the performance?

Yes. I'm using an 2x 1.8GHz Opteron system w/ 8GB of RAM. Right now, I'm
still using 32-bit Linux -- I'm letting others be the 64-bit guinea
pigs. :) I probably will get a cheapie 1x Opteron machine first and test
the 64-bit kernel/libraries thoroughly before rolling it out to production.

As for performance, the scaling is magnificient -- even when just using
PAE instead of 64-bit addressing. At low transaction counts, it's only
~75% faster than the 2x Athlon 1800+ MP it replaced. But once the
transactions start coming in, the gap is as high as 5x. My w-a-g: since
each CPU has an integrated memory controller, you avoid memory bus
contention which is probably the major bottleneck as transaction load
increases. (I've seen Opteron several vs Xeon comparisons where
single-connection tests are par for both CPUs but heavy-load tests favor
the Opteron by a wide margin.) I suspect the 4X comparisons would tilt
even more towards AMD's favor.

We should see a boost when we move to 64-bit Linux and hopefully another
one when NUMA for Linux is production-stable.