Steam using HDD to download items that are stored on an SSD

[u/MarkFaded]

I've noticed lately that my games have been getting updated VERY slow, and when I went into the task manager i noticed that my HDD usage was 100% while my SSD usage was at 2%. The steamapps/downloading folder on my HDD also shows battlefield 6 files in it when it should all be done on the SSD.

Is this a bug because this has only been happening as of recently?

[u/JanwayIsHere]

All to do with available storage on the drive. Each game is different, but some can require 1-2x the size of the game in extra available space to install a patch.

[u/MarkFaded → u/JanwayIsHere]

I was downloading a 29gb update while having close to 300gb in free storage. The reinstall process takes about 20 min for a 120gb game while the update process for a 29gb update would've taken somewhere between 1.5 - 2 hours.

[u/velocity37 → u/MarkFaded]

Depends on game.

29GB update doesn't mean 29GB of space is required. Like Oblivion Remastered has 107GB in a single pak file, so any update that changes that file, even 1 MB one, would need at least 107GB of free space to create the new file.

But only reliable way to get Steam to not use HDD to stage updates is to not have a Steam library drive on HDD. And instead it will just complain that you don't have enough free space when it determines it can't stage an update.

[u/TheWatchingDog → u/velocity37]

Even better you have a 4T SSD with a Steam Directory so it preferes that drive.

[u/Llandu-gor → u/MarkFaded]

well let take some random number for this.

29gb download that is compressed usually at 50% or higher so in reality 50gb of data you already need 80gb of space. then when patching you need the patch (what you downloaded and decompressed) + your old file. as to not corrupt anything and make canceling an update fast and easy it does not overwrite file before finishing. so you need the game size + uncompressed file + a patched copy of each file. making at worst for a 29gb patch that touch every game file a need for 2 x GAME_SIZE + 50gb

some game redownload the whole file instead of providing patch file. etc...

but most of the game an update will cost you the update space + ~50% + patched file

edit: there is also the benefit of killing less your ssd since this is a lot of write making this update write WAY more than 29gb on the ssd

[u/lIIlllIIl → u/MarkFaded]

Checks out. Patch files 30GB + 2 * 135GB (worst case when almost everything needs to be patched, highly likely for such a large update) already scratches the 300GB you have free, and on top of that you still need space to unpack the patch files.

Steam basically had two options, either redownload every changed file completely, or just download the difference and have the user's client apply the patches. The second option is lighter on Steam's infrastructure and the majority of updates isn't that large, so it's what they went with.

As you correctly noticed, re-installing basically forces the first option and may be faster for such large games, as long as your internet connection isn't limited in speed or by a data limit.

[u/Hexicube → u/lIIlllIIl]

30GB + 2 * 135GB

You incorrectly double-counted the install size for required extra space, one of those is already in used space.

Worst-case scenario should just be adding the install size to the download size.

[u/MarkFaded → u/lIIlllIIl]

I find it weird that it didn't happen around 3-4 months ago when i had even less storage available, is this something that was recently added?

[u/lIIlllIIl → u/MarkFaded]

IIRC that's been how it works since 2013 and there have been posts about Steam mysteriously using HDDs here for years aswell. You probably either never noticed or got lucky with your updates.

[u/Dom1252 → u/JanwayIsHere]

not it, even if you're downloading 1GB update to 2GB game and you have 3TB free it'll do it

[u/XmattbeeX]

A few years ago now I set all the drives up with symbolic links to an SSD to stop this nonsense. Awful decision on their part when it starts moving 100s of GBS back and forth with super slow drives

[u/Entegy]

There wasn't enough room to download, decompress, then swap in the files on your SSD, so the HDD is being used as scratch space. Steam is likely keeping the old files around until the updated files are fully in place. The amount of space needed for an update can be double or triple the space the game takes during an update depending on how the game and its files are packaged.

The goal of this isn't installation speed, it's reducing load on Steam's content network. To Steam it's better to have a quicker download and let your PC work harder at unpacking that 29GB than redownloading all 131 or whatever GB.

[u/xMeRk]

Same thing happened to me for the BF6 update. Even with over 600GB of space available on the SSD BF6 is installed on, so it was not ever a question of “not enough space on the SSD”. It seems Steam just uses whatever drive has the MOST free space on it for the update files, logic be damned

[u/based_birdo]

Its a feature, not a bug

[u/MarkFaded → u/based_birdo]

I don't see my games being downloaded 5x slower as a feature

[u/kron123456789 → u/MarkFaded]

It's moving files from your SSD to the HDD to allow the update without asking you to free the space on your SSD. Otherwise it will tell you to free up the SSD in order to update the game.

[u/WereSheep69]

Is your steam client on the SSD too? Mine had auto installed on the HDD and I had all kinds of issues, moving the client to the SSD fixed this and more

[u/Iescaunare]

I had this happen, but with an SD card on my Lenovo Legion Go. A 2 minute update would take literal hours. I had to stop using an SD card.

[u/VukkoPLant]

If you would want to force a faster update by choosing the drive yourself, find the .acf manifest file for your game (google the game ID) in one of the steamlibrary folders (probably where that game is installed) and edit it by adding an entry called "StagingFolder", similar to other entries in the file. The value should be the number of the drive you want to use - the numbers start from 0 and only the disks you linked in your Steam count. So you would have 0 for C:, 1 for E:, 2 for F: or whatever.

https://steamcommunity.com/app/393380/discussions/6/1742260231436827092/ here are the details.

And yeah, this reverts on every game update as well... It's a pain.

[u/coolmouse7777]

I had this problem several years back. Just remove your HDD from stem library and it will solve this issue.

[u/Svensk0]

same here...is your hdd big with a lot if not the most free space? steam somehow chooses that automatically over anything else

[u/MarkFaded → u/Svensk0]

Yup

[u/nou_spiro]

This is something that irritates me too. Like I have fast SSD drive for my games and HDD as a storage for games that I currently do no play. And instead of quick patching of files on same disk it first must copy them over to second one and then copy them again to first disk. This should be disabled.

[u/mabarskuygan]

Well if the game stored in the SSD but the update use your HDD (I assume you also add the hdd to steam) it's kinda weird, you should talk to support.

If its the reverse I would be kinda spooked tho, it can use much TBW of the SSD if I don't want to.

[u/Koolmidx]

I don't know how you managed to get disk2 as the C drive.

[u/Kantrh → u/Koolmidx]

It's how windows orders them. Sata gets put as disk 1

[u/Koolmidx → u/Kantrh]

If you install windows with all three drives connected, maybe. You should only install windows with the intended drive connected and all other drives physically disconnected from the system.

[u/Samraat1337]

It's because you have your hard drive marked as a location for "steam library" i.e a location for your games to be installed

once that's done it uses your HDD as scratch space to download/install patches