SSD can't keep up?

[Kelarik]

I've been trying to get some recording going (3440x1440 and 2560x1440, at 60fps) and I think I might be hitting a performance limit on the SSD that I'm capturing to, but I figured I'd ask to see if I'm missing something simple. It'll record nice and smoothly for a while, then a Storage bottleneck warning appears, before going back to smooth recording again. On the playback it runs fine, then stops for a second, and jumps to wherever the recording smoothed out again. I mostly use the latest MagicYUV codec at 4:2:0 but I've also tried x264vfw at 4:2:0, and had the same result.

The capture drive is a SanDisk Ultra II, which houses neither my OS or the game being captured, with a benched write speed of 480MB/s. I've also tried capturing to my primary Samsung 850 EVO (486MB/s bench) and that seemed to be able to keep up, but with that being a small drive, space isn't quite up to that level of capture. A small RamDisk also seemed to behave, but it doesn't take long to fill a 12GB RamDisk at 1440p60 with minimal compression. Splitting the recording over both drives with RawCap also ran into the same problem, so I do think that the SanDisk drive is the culprit. It's not the most expensive drive on the market, so perhaps it can't handle that level of sustained write? I kept an eye on the Resource Monitor while recording, and did notice the Queue Length on that drive absolutely shoot up when the stutter happened.

As I said, though, it's mostly a sanity check to make sure I've not missed out on something obvious before I go dropping a load of cash on either another Samsung SSD, since the EVO seems to work fine, or just full-on NVME drive.

[Takedown]

Just in case, post your logs
http://forum.exkode.com/index.php?topic=2.0

When using MagicYUV you may be hitting the limit of what that drive can write.  ( It looks like that sandisk has a sustained write speed in the low to mid 200's ).  As for when using x264, it shouldn't be happening then unless you're using q0 or maxing your cpu.

Other forum members have more experience than I with lossless recording though.

[Kelarik]

Sure I'll attach the environment info, why not! What you've said about the sustained write may indeed be the cause, since the Samsung drive most likely stomps the SanDisk one in that regard, though would that limit still be a thing if I'm recording across 2 drives using RawCap?

When I used x264 I did basically crank it as hard as it can go, because I want close to lossless. Maxing CPU isn't likely, I've got a 5930K at 4GHz which should be able to handle whatever gets thrown at it

[Takedown]

You're right the raw cap should rule out the bandwidth issue, but *shrugs*.   I'd test x264vfw with regular lossy settings like this except leave "zero latency" off and set the quality to 15.
https://www.bandicam.com/faqs/vfw-x264-xvid-divx-h264-codec/best-x264-codec-setting-recording.gif

Record to the Sandisk and see if that changes anything.

[ClassifyLP]

Have you tried writing just any very large file onto the Sandisk? Sustained writes seem to be difficult for some SSDs.