what to look for when buying an ssd for magic

[blackdot]

i'm comparing different ssds and I'm wondering: If magic reads stuff from the ssd during a performance, is that random or sequential or a mixture? on what ssd specs should I focus?

thanks

[Sadler]

I would say that any SSD would improve things but I would think seek time on random access would be one of the crucial aspects. Since magic cannot know which scene you will choose next you'd want to cut down the time to get a new scene into memory. Once a video is opened, loading into GPU memory (Eric can correct me if I'm wrong) will handle efficient playback. The bitrate for 60fps @ 1080p is around 12MB/s and assuming that Magic can start playing at the first key frame even a regular hard drive (around 100 Mbps) can cope with this. An SSD would give more space to breath and allow one to load multiple videos efficiently especially with data rates around the 600Mbps (or the fast m.2 ssd can deliver 30Gbps!).

But, if your scenes have any sort of complexity (images, fonts, IFS, shaders, video, models) then seek time is your bottleneck.

Disclaimer: I'm not an expert on these things but this is my understanding.

[Magic]

I guess you'd probably want a mixture of sequential and random. Sequential would be for reading/writing a big file or big chunks of a file at once (such as a video), whereas random would be for jumping around between files (which can happen even during a sequential operation as a temporary interruption). But, for example, if you are using the JpegFolder module, it's definitely a mixture of sequential (to read one file) and random (to go to the next file, which might be on a different part of the drive).

Also, it depends on how your operating system handles things, but many times, big files aren't stored contiguously. This is called "fragmentation" -- you've probably heard of it. Fragmentation results in the need for random seeks, so unless you are always defragmenting your drive, it's possible that one video file has different chunks in different places on the drive.

Overall though I wouldn't worry too much... pretty much any SSD is better than a traditional hard drive. If you've never booted Windows or OS X from an SSD before, you'll be amazed how much faster it is.

Once a video is opened, loading into GPU memory (Eric can correct me if I'm wrong) will handle efficient playback.

The video decoding takes place on the CPU/GPU, but the loading still happens from the drive, because videos are usually too large to fit entirely in memory. During playback, the drive is accessed quite a lot -- pretty much every video frame (or at least small groups of frames). An SSD always makes video playback faster, especially when playing multiple videos at the same time.

[blackdot]

I'm already using an ssd but it's too small (and also my OS-ssd), so I'm looking into buying a new one. from what I've heard you shouldn't defragmante SSD's as you'll use up write cycles. considering this, and what you've said, and that i use more jpgfolders than movies, I conclude that the random read speeds, and also the IOPS are probably more important in my case .

thaanks.