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Writes to ram drive SLOW with 2 inputs...?

Posted: Thu Nov 22, 2012 12:38 pm
by jmc2
W7/64 32G ram
X79 Sabertooth
3930 [email protected]
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I thought I would be able to set a number of drives writing to my ram drive
with no problem but as soon as I start just one additional write to the ram drive
it all slows down.

One seq. write 4GB/sec but 2 writes are slower then what my physical drives are capable of. :(
Samsung 3TB drives (1TB per platter) can write at 170-200 MB/s.

I guessing some kind of windows file handling issue.
Want to see what others think about the bottleneck.

Thanks
jmc2

AS SSD Benchmark 1.6.4237.30508 (on a RAMDRIVE)
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Name:
Firmware:
Controller:
Offset: 1024 K - OK
Size: 0.00 GB
Date: 11/22/2012 11:46:14 AM
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Sequential:
------------------------------
Read: 3832.98 MB/s
Write: 4012.86 MB/s
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4K:
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Read: 172.34 MB/s
Write: 167.65 MB/s
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4K-64Threads:
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Read: 249.91 MB/s
Write: 252.13 MB/s
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Access Times:
------------------------------
Read: -.--- ms
Write: 0.023 ms
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Score:
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Read: 806
Write: 821
Total: 2125
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Re: Writes to ram drive SLOW with 2 inputs...?

Posted: Thu Nov 22, 2012 1:10 pm
by Ari Atari
I believe someone else posted here showing that sometimes running games installed on ram disks loaded slower than those on SSDs. It's definitely something with windows.

Re: Writes to ram drive SLOW with 2 inputs...?

Posted: Thu Nov 22, 2012 1:38 pm
by just brew it!
Probably depends on how the RAM drive is implemented...

Re: Writes to ram drive SLOW with 2 inputs...?

Posted: Thu Nov 22, 2012 2:24 pm
by UberGerbil
just brew it! wrote:
Probably depends on how the RAM drive is implemented...
Yeah, a RAM drive essentially is a device driver for a virtual device, and there lots of ways to fail when writing a device driver -- or, as may be the case here, function but in a suboptimal way. With pretty much any other block storage device your code ends up waiting on the hardware because it runs so much faster; but with a RAM drive that's not the case, so threading issues that go unnoticed (or don't exist) with conventional storage could become problematic. (And threading issues could be a whole range of things, from serialization within the driver itself to algorithm design that ends up gated by serialization in OS calls). There may be something else at work, but have you tried a different RAM drive implementation?

Re: Writes to ram drive SLOW with 2 inputs...?

Posted: Thu Nov 22, 2012 3:14 pm
by Ryu Connor
FWIW: Link

Asus recommends two different RAMDisk vendors for their X79 boards.

Re: Writes to ram drive SLOW with 2 inputs...?

Posted: Thu Nov 22, 2012 4:49 pm
by jmc2
Hmm, thanks for the thoughts to all and the link.
I'm using Dataram software.

Guess I am going to have to check out the other software in the link.
Hope they have free demos for testing writes.

Thanks again,
jmc2