erichileman

5 ms·

1.
by erichileman 2y ago
Why not run something like 8 x L40's for $4,750 a month from a bare metal provider like latitude.sh? This seems far more cost efficient and flexible.
2.
Z1d 4GHz “sustained all core turbo” either a mistake or broken
1 points by erichileman 8y ago|2 comments
3.
by erichileman 10y ago
See the other comment above re: perf stat. Working on the event descriptors to see and confirm the l1/l2 cache hits/misses.
4.
by erichileman 10y ago
Unfortunately <not supported> Performance counter stats for 'php56 index.php': 394.588620 task-clock (msec) # 0.983 CPUs utilized 226 context-switches # 0.573 K/
5.
by erichileman 10y ago
Memory seems likely. On the E5 php 5.6 in top we see sys at 15%. On the E3 php 5.6 in top we see sys at 7%. On the E5 php 7 in top we see sys at 13%. We are exploring memory perf more now.
6.
by erichileman 10y ago
We have not compared on bare metal.
7.
by erichileman 10y ago
We built 5.6 with -O2 -march=broadwell -mno=avx (had to remove, probably pecl ext issue). There was about a 15% performance gain. Nothing that would explain the large difference between E3 and E5.
8.
by erichileman 10y ago
>>gcc -march=native -Q --help=target >>march=silvermont gcc native thinks this e3 is silvermont, a low power SoC.
9.
by erichileman 10y ago
Correct. We are going to build using the correct -march flags: https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html
10.
by erichileman 10y ago
Found this and will try it: https://github.com/centminmod/centminmod/commit/755dd9e87eac...
11.
by erichileman 10y ago
We thought that as well. The E5 has 4 memory channels max bandwidth of 51.2 GB/s. The E3 has 2 memory channels max bandwidth of 34.1 GB/s. But we see a dramatic difference in single core tests. Our virtual machines have 2 cores
12.
by erichileman 10y ago
The binaries are from remi repo. We have a template we provision from. I used the same template on each virtual machine. PHP 5.4.45 (cli) (built: Sep 19 2016 15:31:07) PHP 5.5.38 (cli) (built: Nov 9 2016 17:32:11) PHP 5.6.28 (cli) (built:
13.
E3-1240 v5 3.50GHz single core perf worse than E5-2650 v2 2.60GHz PHP 5.X
24 points by erichileman 10y ago|21 comments