Interesting RAM observation

[zachmullin]

About a year ago I was looking to buy an XPS 13, specifically the mid-year model with an i5, 8GB RAM, 128GB SSD.  Long story short I accidentally bought the model with the same storage and CPU but 4GB RAM.  It was a very unique circumstance that didn't allow me to cancel the order.  So as soon as I got the machine I was paranoid I was going to be bottle-necking the HELL out of my CPU.

 

To my surprise, absolutely not.  As I said, I've been super paranoid about the memory on my laptop.  So every time I did something intensive, I had a task manager open and was monitoring the memory usage.  I NEVER past 3.6GB usage.  Never.  Even at 100% CPU while rendering or encoding videos, gaming (as much as my iGPU could handle, Rocket League being the most intense) I never past maxed out my RAM in a full year with the machine.  I even tried streaming and that didn't hit the limit.

 

To be fair, I never had more than 4 programs running at once, or more than 10 tabs open.  But even with 4 programs and 10 tabs open it was always my CPU that hit 100% first.

 

So I am just wondering people's opinions on why I haven't had any trouble.  Is it just that my CPU (i5 6200U) is too weak to use more than 4GBs?  Or is it Windows 10's improved memory management?  Or is it simply the tasks I'm doing (editing, encoding, some gaming)?  I'm interested to hear what you think.

[themctipers]

If you did my workload, prayer 

 

I mean, it might be enough for you but for me, I need atleast 8gb (and even that's a bottleneck)

 

i idle at 12gb  

[zachmullin]

15 minutes ago, rrubberr said:

That doesn't mean there isn't a 20 gig swap. 4 gb hasn't been enough since 2004, and these days 16 is laughable for professional work.

But yet it IS usable on this machine..?

[straight_stewie]

22 minutes ago, zachmullin said:

 As I said, I've been super paranoid about the memory on my laptop.  So every time I did something intensive, I had a task manager open and was monitoring the memory usage.  I NEVER past 3.6GB usage.  Never.  Even at 100% CPU while rendering or encoding videos, gaming (as much as my iGPU could handle, Rocket League being the most intense) I never past maxed out my RAM in a full year with the machine.  I even tried streaming and that didn't hit the limit.

To be fair, I never had more than 4 programs running at once, or more than 10 tabs open.  But even with 4 programs and 10 tabs open it was always my CPU that hit 100% first.

There is alot more going on then you would think, and windows task manager CPU utilization statistics really just come from calculating the percentage of operations that are just NOps (and excludes OS operations). You can theoretically get to 100% cpu utilization just by writing a program that just does register transfers on 4 asynchronous threads and then going into the task manager and moving the threads to unique physical cores.

Basically what's going on is this thing called memory paging. You can save "pages" of RAM to the hard drive and then load new data (or perhaps, even a page) into RAM for use. You can then "swap" pages into and out of RAM, to extend the virtual size of memory. This is what Windows "Swap File" is. It's just a file full of all of the pages of RAM data. This technique is very slow, but it doesn't cause your computer to crash like trying to "overfill" RAM would.

You get to 100% utilization of CPU before you use all 4 gigs of RAM for a couple of reasons: 

1. Not all four gigs of RAM is in userland. About half a gig or so of it is in OSland when just idling, potentially more (which means that you can't actually use all 4 gigs anyway)
2. The CPU has to do operations to handle memory paging, so just doing that adds to the CPU utilization, while not actually accomplishing much work.

[HelplmChoking]

23 minutes ago, zachmullin said:

About a year ago I was looking to buy an XPS 13, specifically the mid-year model with an i5, 8GB RAM, 128GB SSD.  Long story short I accidentally bought the model with the same storage and CPU but 4GB RAM.  It was a very unique circumstance that didn't allow me to cancel the order.  So as soon as I got the machine I was paranoid I was going to be bottle-necking the HELL out of my CPU.

 

To my surprise, absolutely not.  As I said, I've been super paranoid about the memory on my laptop.  So every time I did something intensive, I had a task manager open and was monitoring the memory usage.  I NEVER past 3.6GB usage.  Never.  Even at 100% CPU while rendering or encoding videos, gaming (as much as my iGPU could handle, Rocket League being the most intense) I never past maxed out my RAM in a full year with the machine.  I even tried streaming and that didn't hit the limit.

 

To be fair, I never had more than 4 programs running at once, or more than 10 tabs open.  But even with 4 programs and 10 tabs open it was always my CPU that hit 100% first.

 

So I am just wondering people's opinions on why I haven't had any trouble.  Is it just that my CPU (i5 6200U) is too weak to use more than 4GBs?  Or is it Windows 10's improved memory management?  Or is it simply the tasks I'm doing (editing, encoding, some gaming)?  I'm interested to hear what you think.

 

Likely because what you're doing doesn't require much RAM. I know that when I used my PC with 4GB RAM (for a week), GTA V was unplayable since it requires lots or RAM. But your workload may just be light enough to get away with it.

[SilentXer0]

25 minutes ago, rrubberr said:

That doesn't mean there isn't a 20 gig swap. 4 gb hasn't been enough since 2004, and these days 16 is laughable for professional work.

i would have to agree with this, and high swap file usage will cause cpu load which could be why cpu usage is so high.

 

edit: @straight_stewie said this already, hadn't read his post.

[Mooshi]

Is the OS even 64bit? Chrome alone burns over 5GB of ram.