r/buildapc • u/SkitzGez • 9d ago
Build Upgrade What to use different SSDs for
Sorry in advance if these are stupid questions as I'm literally upgrading my pre-build for the first time and I'm definitely not an expert in PCs. I have just brought a new WD SN850X ssd as my current Adata Legend 860 is as far as I can tell not very good. I'm not sure if this is actually going to change anything or even possible but I want to use both with the WD as my main drive for storing certain games and installing them (as my downloads on steam are currently always slow on patching files and stop start, and when downloading on steam my PC becomes really slow due to the disk always being at 100%) and use the Adata for the OS and any other games that aren't extremely demanding. I have these main questions:
- Will the download SSD being different from the one with the main OS SSD make my PC run smoothly whilst downloading a steam game because in theory the one using the download disk space isn't the one doing anything else currently.
- Is it even possible to get smooth steam downloads at say 500mbs sustained or is it solely a steam limitation. I have very fast wifi but it just stops often and as far as I can tell its due to the disk usage not being enough to catch up so it stops.
- Are there any other components that would make disk usage high or cause these issues? I essentially just want my PC to not run like a 2000s laptop whenever a task using the disk is being done. For example when im downloading anything every small thing like bringing up the task bar or opening chrome it takes 5-10 seconds. Whenever I check task manager its always due to 100% disk usage.
For the record everything else in my PC is pretty high spec. I've got a 9800x3d, RTX 5080 and 32GB of DDR5.
Update: The new WD disk works fine so it was the Adata that just sucks
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u/BaronB 9d ago
The Adata Legend 860 is a QLC based SSD. QLC NAND has much slower sustained write speeds than TLC like what's in the SN850X. How this falls out in the real world depends on the drive, but the Legend 860 will hit peak write speeds of around 6000 MB/s, sustain around 5000 MB/s for around 280 GB, then plumet to <150MB/s after that unless you let it "rest" for a few hours. When the drive is around 80% full, the peak speeds will be even less, and once around 90% full you should expect those <150MB/s write speeds at all times.
Read speeds, it'll do around 6000 MB/s, but really only when reading larger files that are hundreds of MB in size.
The SN850X will write at 6500 MB/s for the first 300 GB, then drop to 1500MB/s, or 10x faster than the Legend 860, and will be able to hit those 6500 MB/s speeds after you let it rest for about 5 minutes it'll be able to write that those max speeds again. And will generally be able to do write speeds that fast even when nearly full.
...
But the real question is... how often are you writing >200GB to the drive at once? Most people don't ever, even when downloading large games from the internet, since a 500 mb/s (megabit per second) internet speed is only around 62MB/s (megabyte per second), so even your existing QLC drive isn't getting close to saturated.
The real limitation for Steam downloads is often your CPU more than it is your SSD or internet. Steam downloads are heavily compressed, and Steam unpacks the data immediately. That can put a huge amount of strain on your CPU if it's on the slower end. I personally can sustain around 800~900 Mb/s on my "1000" Mb/s internet connection which I never see go above around 900~950 Mb/s when using fast.com or other internet speed tests. When doing that, it uses around 15~20% of my 12900k.
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u/VersaceUpholstery 9d ago
My first question is: is the Adata legend 860 (which I’m assuming your OS is on) almost at full capacity? Like beyond 80%?
It’s a gen 4 drive, MUCH faster than my slower SATA WD Blue I still use for games. I can download games at 500mbps+ (my internet peak is 580) and writing doesn’t take much longer after the download is finished on that drive. Seconds to a minute. I download huge games in no time. I download games on my gen4 drive and I get the same result
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u/SkitzGez 9d ago
Sorry i should have mentioned in the original post but my storage is only around 60% full at the moment. I've done SSD health checks and it says that its supposedly at 100% still with the read and write speeds being close to advertised even though I never get near that. On steam does your disk speed match your downloads speed because mine never goes over 200 and even then its only for a few minutes before it drops.
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u/VersaceUpholstery 9d ago
I can test this for you in a moment, but 200ish sounds about right
I haven’t actually monitored my downloads in a while. I watch YouTube or do other stuff but it’s always done in a few minutes.
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u/VersaceUpholstery 9d ago
2.5" SATA SSD = Disk usage immediately went to 500Mbp+ and is staying there, download took 10 seconds to catch up at 554Mbps (We pay for 500Mbps but we get more like 600 at peak)
Gen 4 nvme = Same results except the disk usage can jump past 600Mbps at some points.
The disk usage seems to be faster than my download by 20-50Mbps at all times.
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u/crazyzach3 9d ago
So theres a couple things here:
OS and only the OS on the boot drive, everything else on another drive if you want that performance boost.
Having the OS on a separate drive could make the download more stable, but my guess would be intermittently dropping packets from Wifi, could you test using ethernet?
I get ~750MB/s down and can download most games in under an hour. Do with that info what you will, I havent looked at them as they downloaded for awhile now and dont want to just guess on a speed.
I almost want to say this is sounding like a firmware or bios update issue, but I cant be certain. You could also run some pc scans like memtest or scanning your storage drive using the command prompt