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Search speed in AMD

Posted: Wed Mar 25, 2020 5:33 pm
by Krzysztof Grzelak
I have such a request and question. I write immediately that I am not a programmer. I have a processor AMD Ryzen Threadripper 1950X. I am looking for information on how to increase the search of 1 core in the processor AMD Ryzen Threadripper 1950X. Please, if possible, a code in C ++. Thank you in advance for any information.

Re: Search speed in AMD

Posted: Thu Mar 26, 2020 2:39 pm
by mar
My experience with AMD so far is that AMD loves everything cached in registers.
Any memory access (assuming in L1) is much slower than on Intel, or perhaps it's the other way around and AMD is much faster when executing reg-reg opcodes)
Optimizing compilers do this for you, obviously, so I don't see how this would help.
I've also heard that BMI2 is emulated on AMD, thus much slower than on Intel (I don't use BMI2 in my program).

Re: Search speed in AMD

Posted: Fri Mar 27, 2020 12:54 am
by Michael Sherwin
mar wrote:
Thu Mar 26, 2020 2:39 pm
My experience with AMD so far is that AMD loves everything cached in registers.
Any memory access (assuming in L1) is much slower than on Intel, or perhaps it's the other way around and AMD is much faster when executing reg-reg opcodes)
Optimizing compilers do this for you, obviously, so I don't see how this would help.
I've also heard that BMI2 is emulated on AMD, thus much slower than on Intel (I don't use BMI2 in my program).
I can verify that BMI2 runs at only 2/3 of the node rate of the popcount version on my AMD 3950x.

Re: Search speed in AMD

Posted: Fri Mar 27, 2020 4:13 am
by Dann Corbit
ipman chess shows that the AMD BMI mode stinks, stanks, stunks.