SSDs and multitasking

[VectraMan]

Permie co have given me a 2xQuad core Xeon PC with an SSD, Windows 7x64 and 4GB RAM. However, one thing I've noticed is despite having 8 CPUs to play with, multitasking whilst doing a large Visual Studio build kind of sucks.

It's somewhat suprising, not least because the main thing that impressed me with Windows 7 (as I experienced on my much more modest dual core laptop and desktop), is that the GUI would remain responsive whilst doing something disk intensive like a build. But that doesn't seem to be the case on this machine.

Is it possible that a faster SSD means that much more of the system resources are being used on the disk system, therefore the rest of the system becomes less responsive? Whereas a slower hard disk would allow much better multitasking.

Thoughts?

[d000hg]

What language? I don't know about .net but with C++ it would depend how many cores the compiler is using which is a switch, on 2008 anyway. When I compile a regular project VC++ uses 1 core by default and the system runs absolutely smoothly - I can even play an intensive 3D game without it stuttering. OTOH if I set the project to compile with 4 threads (I have a single quad-core) then things get a lot more stick since VC++ is obviously running all cores at 100% to work as fast as possible.

[VectraMan]

It's C++ .NET, just to confuse you. They didn't know about the secret switch on VS2005, and so most of it is only compiling with a single core. But it's the same with multi core compile switched on.

Which means 7 out of 8 processors are largely idle, so it can't be an issue of CPU multitasking.

[doodab]

What SSD is it & what is the small random write performance like? A large build is going to delete and write a lot of intermediate files, so if it's one of the slightly duff ones or has otherwise slowed down that could be a factor. I have an intel one and find that occasionally it will slow almost to a halt when copying files around and I need to run the intel SSD optimizer to get full speed back.

[VectraMan]

It's a Samsung something or other, and not a brand new one so maybe it isn't great. But I would have thought random access would be the area where an SSD is vastly superior to an olde fashioned physical disk, even though all the hype about SSDs always focuses on the read/write speed.

Edit: 5000th post! I am a God.

[Clever Hans]

Some non-SSD pointers via google, eg. here* to try first, o omnipotent one.

But it does sound like the temp file issue described above - I think low end SSDs are not always high speed at all times and under all conditions.

So you could attempt to prove this by moving the temp folders to a secondary (non-SSD) HD, or even experiment with a ramdisk (make sure you choose one that is persisted on boot if necessary).

eg. RAMDisk - Software - Server Memory Products & Services - Dataram

(Free for non-corporate use to 4GB if you want to try it).

If the temp folder tweaking sorts it, then stick with the secondary hard drive, or use the info to blag a top end SSD.


*a very short time later, this post now appears as a backlink on that page which is a bit creepy.

[xchaotic]

4GB is not that much these days, you can probably add another 2x2GB for you lunch money.
Finally you can try to manually set the VS affinnity to use Core #3 or sth rarely used, so that the OS and non-multicore aware software can use a core other than the Visual Studio.

I am also betting that your SSD is crap in random writes and probably deteriorated since new due to it being an early model with no TRIM support and/or internal garbage collection, you could try some utility to try and restore some of the performance.

Also the latest shiny in SSD is >500MB read/write which is eons better than earlier models, but more importantly 60000 IOPS which is usually quite handy when building/compiling a project.

[JoJoGabor]

Get perfmon out and check your disk perofmrnace. Look for any disk queues greater than 2 and disk reads or writes taking more than 0.01 of a second. If they are all ok look at CPU and memory usage, CPU queues etc

[OwlHoot]

Surprisingly (as it has no moving parts), SSD cards are notoriously unreliable and are almost guaranteed to fail within a year.

I saw a blog article on this, but don't now have the reference. NickFitz probably knows though.

[d000hg]

Surprisingly (as it has no moving parts), SSD cards are notoriously unreliable and are almost guaranteed to fail within a year.

I saw a blog article on this, but don't now have the reference. NickFitz probably knows though.

I bet he doesn't because that's crap.