How many HD channels from an antenna can I record simultaneously if I have 8 tuners?

[xrqp 11]

I got an antenna, two (2) of the  HD Homerun Connect 4K for a total of 8 tuners, Emby Premiere DVR w Emby guide, wired ethernet w Gigabit switches, intel i3 computer with SATA hard drives.

What is the most HD channels a good home system can record simultaneously (assuming 1080i, or 720p)?
I just started trying this and it is not going well yet.

What is usually the bottleneck:  hard drive data flow, gigabit ethernet,  something else?

[rbjtech 5287]

Your primary bottleneck is going to be disk I/O

As an experiment, try recording on different physical disks - ie 4 tuners on one disk, 4 on another.

Use perfmon to watch disk I/O live (and other areas as you see fit) as you are recording and you'll easily see when and where you hit a bottleneck.

 

 

 

Edited March 4, 2021 by rbjtech

[Sammy 790]

I've recorded 8 HD Channels before. I use a 1Tb NVMe for recording then process and move the recordings to a Spinner Drive and pint Emby there.

[xrqp 11]

Thanks for the replies.  I also posted at Silicon Dust and got this useful quantitative reply there:

Quote

No problems with a home network supporting 8 x 1080i streams at once assuming a GigE switch.
1080i is typically around 16Mbps so 8 recordings at once is still only 128Mbps.
Disk speed should be fine as well with modernish drives - 128Mbps is 16MB/s.

Edit: I replaced my 2-way splitter and it works great now.  I recorded 8 channels of HD simultaneously (4 at 1080i, and 4 at 720p) and checked the results and all 8 were good recordings.   During this time, my Unraid NAS reported that my CPU  (i3 7100T) ran at 80%, hard drive about 10MBps, and ethernet at  88Mbps.  I guess the video is compressed more than the quote above.  All good news.  This is GREAT!

Edited March 5, 2021 by xrqp

[Carlo 4561]

I've had over 20 recordings in Emby at the same time and it's not uncommon to have 8 to 10 recordings in progress at the same time for me.

IO is the basic problem but with fast SSD it can be done.  I've got dedicated SSDs for the OS, for transcoding and for DVR so this helps.

[Ronstang 294]

On 3/5/2021 at 9:34 AM, cayars said:

I've had over 20 recordings in Emby at the same time and it's not uncommon to have 8 to 10 recordings in progress at the same time for me.

IO is the basic problem but with fast SSD it can be done.  I've got dedicated SSDs for the OS, for transcoding and for DVR so this helps.

I have six going many times on my HTPC which at the same time is usually running full time converting said recordings to compressed MP4 while I'm using the same machine to edit and move the TS files out of my recording depository and watching at least one stream on Emby in another room.  Like Cayars said it's all about IO.  I also  have my OS, transcoding temp directory, and recording depository all on separate fast SSDs.

[xrqp 11]

My SSD is not being used for the recordings.  I only use SSD for the program to run in.  Only spinning hard drives are used for my recordings.  And I still get 8 HD recordings at once which is plenty for me.  If 8 HD recordings only creates 10MBps, I am guessing a spinning hard drive could do many more (15 or 20 or more?).  So I imagine 99% of users do not need SSD to record to.  I don't do transcoding so I don't know if SSD helps with that.

It is great that we can do this.  Having so many tuners able to run at once really helps with shows set to start early and run late and overlap with other recordings.  I am also real pleased with HD HomeRun can do 4 tuners per tiny device.  And I only need one splitter to get 8 tuners and so only loose 3.5db of signal.  Home theatre PC is a big hassle for me, so this is a moment of joy that makes it more bearable.