Windows 10 RAM compression

[Mattias Westlund]

Here's an interesting observation, make of it what you will.

Ever since launch, Windows 10 has had a feature called RAM compression, wich in a nutshell means it compresses chunks of used RAM to conserve memory. I've never really thought much about it as it's always seemed to work as advertized.

However, to my dismay I recently disovered that some of my most memory-hungry REAPER projects (like Lore) didn't load anymore. Attempting to load them, the RAM usage kept rising and rising until it was well above the size of my installed RAM and REAPER crashed with an "out of memory" error message. First, I was stumped. These projects have worked fine before -- I created them on this machine, with the same amount of RAM -- so I concluded it must be a software issue.

Updating various plugins and even going back to older versions made no difference. Opening the projects in the trial version of REAPER 6 made no difference either. So I started suspecting that a system update in recent months (I was last working on Lore back in November) must have changed something in the way Windows handles memory. Researching this, I came across a mention of how to disable RAM compression. Which I did, just for troubleshooting purposes. And lo and behold, the projects loaded fine with it off!

I should mention that I have no idea what's going on here, technically. It might not be Windows that's at fault, but rather some obscure issue with some plugin I'm using. But I'm leaving RAM compression off as it seems to have done the trick. I can understand why it would be desirable on a system with say 4 or 8GB, but I have 16GB and I don't really see the point in Windows spending CPU time to save a 100MB here and there as it's nowhere near using all available RAM anyway. There's 13.5 gigs free, just use it!

I switched it off a few days ago and have yet to notice any adverse effects. On the contrary, my CPU runs around 6°C cooler than before so there's definitely less load on the processor.

So in closing, I'm not recommending everyone to turn off RAM compression. If you're not having any issues with it, leave it alone. But it might be worth a shot if you run into mysterious RAM-related problems.

[Samulis]

Thanks for sharing this! Certainly there must be others out there who have had this issue.

I wonder if there's a memory leak with the interaction between Reaper and Windows 10. Very strange that a feature promising one thing results in causing the opposite to occur!

[Mattias Westlund]

(02-08-2020, 06:24 AM)Samulis Wrote: Thanks for sharing this! Certainly there must be others out there who have had this issue.

I wonder if there's a memory leak with the interaction between Reaper and Windows 10. Very strange that a feature promising one thing results in causing the opposite to occur!

That was kind of my thinking as well. Maybe an update to Windows changed something in the way RAM compression interacts with some programs. I really doubt that REAPER itself has a memory leak. I've been on v 4.78 for years now and I'm sure I would have noticed it before.

Edit: Here's a thought. Maybe REAPER somehow doesn't "see" that Windows is compressing memory and only notices that RAM usage is rising to unsafe levels? I mean, perhaps it only knows how much RAM it allocates to begin with and has no idea what Windows does with it afterwards, if that makes sense.

Edit 2: That still doesn't explain why the projects seem to use more RAM with compression on, though.