SSD but still i am getting disk over load.

[zhanka]

Hello,

Recently ordered new Dedicated server from OVH: http://www.ovh.co.uk/individual/products/eg_ssd.xml

It cost around 250GBP with windows server 2003 64bit.

I tested Utorrent 1.7.7 and 1.8.1

I was Downloading a torrent 17GB with speed of 34MB/s, after 20 seconds disk went over load and download speed came down to 1-2mb/s

As OVH stated, SSD drive is 22 times faster then Sata2, then why i am still getting disk over load ?

I changed cache to 1023MB, still i am getting disk over load.

I changed cache to 1023MB, UTorrent crashed

Please help me solve this issue.

Regards

Zhanka

[thelittlefire]

SSD is fast... not good at sequential. Superior at random seek... What else does your Disk Cache pane look like?

If 1023 still gets overload how can it crash? I'm not sure you changed the right value. uT like all 32 bit programs can't allocate > 2 GiB of RAM, so you should be VERY careful setting disk cache > 15-1700

[zhanka]

I made it 1500.

I was downloading at 53MB/s

after 20-25 seconds, Disk went overload and download speed came to 1-2MB/s again.

Something strange going on, Disk should not show disk overload on a SSD drive

[thelittlefire]

Torrents are random data. Seeking... is bad? You didn't answer my question/show the Disk Cache pane.

[zhanka]

I removed: Write out untouched blocks every 2 minutes and Reduce memory usage when the cache is not needed

still same result.

[DreadWingKnight]

You are using an unsupported version of uT.

[zhanka]

I did mention in my first post, i used UTorrent 1.8.1 also.

I am getting the same result !

[DreadWingKnight]

Your disk cache screenshot says you aren't using 1.8.1

New screenshot with 1.8.1 please.

[olmari]

Good info about SSD performance here: http://torvalds-family.blogspot.com/2008/10/so-i-got-one-of-new-intel-ssds.html

I quote the most important part:

"But no, forget about the throughput figures. Others can match - or at last come close - to the throughput, but what that Intel SSD does so well is random reads and writes. You can do small random accesses to it and still get great performance, and quite frankly, that's the whole point of not having some stupid mechanical latencies as far as I'm concerned.

And the sad part is that other SSD's generally absolutely suck when it comes to especially random write performance. And small random writes is what you get when you update various filesystem meta-data on any normal filesystem, so it really does matter. For example, a vendor who shall remain nameless has an SSD disk out there that they were also hawking at the Kernel Summit, and while they get fine throughput (something like 50+MB/s on big contiguous writes), they benchmark a pitiful 10 (yes, that's ten, as in "how many fingers do you have) small random writes per second. That is slower than a rotational disk.

In contrast, the Intel SSD does about 8,500 4kB random writes per second. Yeah, that's over eight thousand IOps on random write accesses with a relevant block size, rather than some silly and unrealistic contiguous write test. That's what I call solid-state media."