gmail.com]
Sent: Monday, January 16, 2017 12:00 PM
To: Cohn, Robert S
Cc: r-devel@r-project.org
Subject: Re: [Rd] accelerating matrix multiply
Hi Robert,
thanks for the report and your suggestions how to make the NaN checks faster.
Based on my experiments it seems that the "break"
2017 12:00 PM
To: Cohn, Robert S
Cc: r-devel@r-project.org
Subject: Re: [Rd] accelerating matrix multiply
Hi Robert,
thanks for the report and your suggestions how to make the NaN checks faster.
Based on my experiments it seems that the "break" in the loop actually can have
pos
trix (runif(2),nrow=m,ncol=n)
B <- matrix (runif(2),nrow=m,ncol=n)
print(typeof(A[1,2]))
print(A[1,2])
# Matrix multiply
system.time (C <- B %*% A)
system.time (C <- B %*% A)
system.time (C <- B %*% A)
-Original Message-
From: Martin Maechler [mailto:maech...@stat.math.ethz.ch]
Sent
---Original Message-
From: Martin Maechler [mailto:maech...@stat.math.ethz.ch]
Sent: Tuesday, January 10, 2017 8:59 AM
To: Cohn, Robert S
Cc: r-devel@r-project.org
Subject: Re: [Rd] accelerating matrix multiply
>>>>> Cohn, Robert S
>>>>> on Sat, 7 Jan 2017 16:
> Cohn, Robert S
> on Sat, 7 Jan 2017 16:41:42 + writes:
> I am using R to multiply some large (30k x 30k double)
> matrices on a 64 core machine (xeon phi). I added some timers
> to src/main/array.c to see where the time is going. All of the
> time is being spent in the matprod
> From: "Cohn, Robert S"
>
> I am using R to multiply some large (30k x 30k double) matrices on a
> 64 core machine (xeon phi). I added some timers to
> src/main/array.c to see where the time is going. All of the time is
> being spent in the matprod function, most of that time is spent in
> d
I am using R to multiply some large (30k x 30k double) matrices on a 64 core
machine (xeon phi). I added some timers to src/main/array.c to see where the
time is going. All of the time is being spent in the matprod function, most of
that time is spent in dgemm. 15 seconds is in matprod in some
