Curious about the memory bandwidth of your machine. If you can, I'd be interested in t

<a class="user-mention notranslate" data-hovercard-type="user" data-hovercard-url="/us

That makes sense. Thank you <a class="user-mention notranslate" data-hovercard-type="u

What's the memory bandwidth of your machine? about 1brc HOT 3 OPEN

kennethchiu commented on July 17, 2024

What's the memory bandwidth of your machine?

from 1brc.

Comments (3)

kennethchiu commented on July 17, 2024 1

Ah, just that this provides a baseline. I'm not an expert on maximizing out every ounce of mem BW, but this at least suggest that 12/37 secs will be a hard limit, because you cannot read the data out of memory faster than 37 GB/s, and the data file is about 12 GB.

from 1brc.

dannyvankooten commented on July 17, 2024

@kennethchiu Here it is:

$ g++ --version 
g++ (GCC) 14.0.0 20231231 (experimental)

$ g++ -O2 -march=native membw.cpp -o membw && ./membw

1 thread(s):
    8.94312e+09
    To prevent optimizing out all ops: 2268145617
2 thread(s):
    1.76821e+10
    To prevent optimizing out all ops: 2268145617
3 thread(s):
    2.21497e+10
    To prevent optimizing out all ops: 2268145617
4 thread(s):
    2.61705e+10
    To prevent optimizing out all ops: 2268145617
5 thread(s):
    3.22876e+10
    To prevent optimizing out all ops: 2268145617
6 thread(s):
    3.49681e+10
    To prevent optimizing out all ops: 2268145617
7 thread(s):
    3.38957e+10
    To prevent optimizing out all ops: 2268145617
8 thread(s):
    3.67197e+10
    To prevent optimizing out all ops: 2268145617
9 thread(s):
    3.53458e+10
    To prevent optimizing out all ops: 2268145617

So up to ~37 GB / second for 8 threads.

My machine is a Lenovo Yoga Slim 7 sporting a AMD Ryzen 7 4800U with 16GB of RAM (DDR4, 1600 Mhz).

Now I don't know much about memory bandwidth, so would love to hear the significance of this.

from 1brc.

dannyvankooten commented on July 17, 2024

That makes sense. Thank you @kennethchiu!

from 1brc.

Recommend Projects