Fast forward/rewind performance (hard drive/SSD recommendations?)

Channels DVR Server
#1

On the Apple TV 4K, I’ve noticed that while fast forwarding in recordings by holding the right directional button seems to play the video at a faster speed, rewinding by holding the left button is a more jerky slideshow-like experience. When I originally had the Apple TV 4K, I seem to remember fast forward and rewind performed similarly, with the video playing in fast motion.

Does this happen for anyone else, and are there any settings that may improve this? I did get an external HDD to store my recordings since then, so I’m wondering if it may be related to the performance of that (vs my Mac Mini’s internal SSD, which is fast but small). I am hardwired into Gigabit Ethernet on both the Mac Mini and Apple TV so that shouldn’t be the issue…

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#2

I could be wrong but I think the forward buffer is longer than the rear buffer. Which means you’re going back to the server more when going backwards. Looking at stats I see Channels buffering around 80-90 seconds of forward buffer so skips forward are pretty much instant until you use that up.

#3

This is expected but we're also working on improvements coming soon.

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#4

I tested rewind/fast forward on DVR recordings running off of my internal SSD vs external HDD, and the SSD performs far better. Given that, I figure this is a drive issue rather than Apple TV. It seems the Seagate I got off Amazon doesn’t cut it - are there faster HDDs I should look out for, or should I get an SSD for best performance? Are there any particular specs I should look for? I’d be looking for an external drive as I use a Mac mini for a server currently and don’t really want/need a NAS solution right now.

#5

It depends upon your use case and needs. Personally, I use a 10TB external drive and don't have issues. If speed while RW/FF is important, you may want to look into a solid-state drive. If you often have several recordings/viewings going on at the same time, either go the SSD route, or if you're looking at HDDs, make sure it is CMR, not SMR.

However, I have found the single most important part of the equation to be network performance. Moving from wireless to a hardwired network connection will greatly improve performance. Even if your streaming device can only handle 100Mbps, the reduction in latency and network crosstalk/congestion makes a huge difference.

#6

I’ve been using hardwired Gigabit Ethernet on my server and primary client device (both of which are on the same router), so I think I have the optimal setup there. I’m the only one using this, so I only have one client active at a time, though I do on occasion have one or more recordings going while I view. Given that (and my experimentation) it seems my bottleneck is the HDD. I figured an SSD was the way to go, though I did wonder if a high-performance HDD may work just as well (and perhaps be preferable due to cost/write limits on SSDs). Though I don’t want to give up fast forward/rewind performance…

#7

I did some more testing, and it seems the issue may not be the hard drive, but the format I used. When I set it up, I used exFAT, thinking I might want to move the server to a Shield or Raspberry Pi later. Before I returned the drive, I figured I’d try reformatting the drive as APFS, particularly since I saw some references to exFAT being slow on Macs online. After setting the DVR to use the newly-reformatted drive, the performance I’m seeing now on the Apple TV is almost identical to the internal SSD.

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