On Saturday, June 18, 2016 at 12:21:21 AM UTC+2, gordo...@gmail.com wrote: > > On Friday, June 17, 2016 at 4:48:06 PM UTC+2, gordo...@gmail.com wrote: > > > I am not on a high end Intel CPU now, but when I was I found that with > a buffer size adjusted to the L1 cache size (8192 32-bit words or 32 > Kilobytes) that eratspeed ran on an Intel 2700K @ 3.5 GHz at about 3.5 > clock cycles per loop (about 405,000,000 loops for this range). > > > > My current AMD Bulldozer CPU has a severe cache bottleneck and can't > come close to this speed by a factor of about two. > > > Which Bulldozer version do you have: original Bulldozer, Piledriver, > Steamroller/Kaveri or Excavator/Carrizo? > > One of the original's, a FX8120 (4 core, 8 processor) @ 3.1 GHz. >
Your CPU is bdver1. My CPU is bdver3. by the clock frequency, I assume you were running these tests on a high end > Intel CPU? > bdver3 CPU has some optimizations compared to bdver1, but I don't know whether this affects eratspeed code. Is your IPC lower than 2.80 when you compile https://play.golang.org/p/Sd6qlMQcHF with Go1.7-tip and run "perf stat --repeat=10 -- ./eratspeed-go1.7tip"? Have you tried compiling eratspeed with a new version of GCC to see how it > compares to Clang? > gcc-6.1 is slower. clang-3.9 is able to translate "bits = buf[pos]; bits |= data; buf[pos] = bits;" into a single x86 instruction equivalent to "buf[pos] |= data". > I am currently working on a golang version of eratspeed and we'll see how > it compares; it will be a better comparison that just using my simple > PrimesSpeed test... > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
