Faster Storage and CPU time

[Trigonomancer]

It's a small question but I always wanted to know if having programs on an SSD or M.2 save CPU time. This made sense in my head because the CPU has to waste less time loading things from storage.

[TheGlenlivet]

3 minutes ago, Trigonomancer said:

It's a small question but I always wanted to know if having programs on an SSD or M.2 save CPU time. This made sense in my head because the CPU has to waste less time loading things from storage.

Do you mean it will load faster?  Yes.

At least compared to a hard drive.

[Jurrunio]

I'm not sure why this happens but seems like you've got things wrong on how CPU behaves. A slow storage means the CPU indeed has to wait longer before it gets all the info needed to launch the application, but during the wait the CPU doesn't do much if at all. In other words, using an SSD instead of a spinning disk HDD doesn't save CPU time, but it saves your time.

[Trigonomancer]

2 minutes ago, TheGlenlivet said:

Do you mean it will load faster?  Yes.

At least compared to a hard drive.

I just mean if having to wait less for things to load will save me some CPU time.

[TheGlenlivet]

3 minutes ago, Trigonomancer said:

I just mean if having to wait less for things to load will save me some CPU time.

Then the answer is yes.  It will take your CPU less time to load from an SSD than an HDD.

[mariushm]

With the mention that the operating system usually caches the whole executable in RAM

So the difference will be just time.  And I don't know, I guess if you get the data in bigger chunks from SSD, maybe you get a few less interrupts so a few cpu cycles less to fully load an executable into memory.

 

[Mira Yurizaki]

55 minutes ago, Trigonomancer said:

It's a small question but I always wanted to know if having programs on an SSD or M.2 save CPU time. This made sense in my head because the CPU has to waste less time loading things from storage.

If we're looking at the point of view of just the application, then having a faster storage drive will allow the application to run on the CPU more often because it's waiting less for data to arrive compared to a hard drive. It also depends on what the application is doing though. For initial loading, you can't escape needing to access the storage drive. But if it's streaming data in and out, like say chunks of a map in GTA V, then no. The application will typically have other work to do, so it'll issue a request from the storage drive, do something else, and the storage drive will ping the application that it has the data for it.

 

If we're looking at it from a system point of view, then no. The system doesn't wait for the application to be loaded, it'll just come back to it once it is and the CPU is free to work on other things.