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The problem with streaming high-bitrate content like Blu-rays from a HDD is not the overall sequential speed, but the random access speed.

If you read from different files at the same time, it needs to seek around on the disc, move the read heads constantly - its just going to be slow.


Personally, i can't say i tested this extensively on actual BD movies, but from experience in similar situations, i would not expect more than 2 or 3 BD movies to work (if even that).


I've had issues myself when trying to watch a single movie while copying data onto the same HDD at full speed, was already enough to trip up playback.

I had to adjust my ripping workflow to directly rip onto the media storage network drive, instead of my local drive first, because writing at BD read speeds is OK, writing at full network copy speed is not.
 

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Because the writing software has a RAM buffer that allows ripping to continue while waiting for head write time. You would need some sort of "reading software" that knows to put the >3 BR files into a buffer and read from that. Or move to SSD media storage drives...
 

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Ripping isn't all that sensitive. In playback, if data comes a bit late, your video already lags a bit, and you notice it.

If the writing is stalled and is delayed a bit, the wrting speed goes down, and ripping may take slightly longer, but it doesn't disrupt the process.


Just some guesses, may also be because of write buffers that Windows uses, which allow some kind of "burst" writing, quickly writing larger blocks, instead of always small blocks.
 

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Nev is overly pessimistic, I think.


Any decent player should read in fairly large chunks, hopefully at least 128KiB and preferably 512+KiB.


Most recent HDDs are capable of 40 MB/s throughput with 512KiB random read tests (look at Crystal Disk Mark screenshots if you want to see measurements).


So as long as the player is reading in large enough chunks, you should be able to stream a lot of blu-rays from a single HDD.


Here is a link to CDM results for a couple recent 4TB HDDs:

http://www.legitreviews.com/article/2182/5/


And here for a 3TB WD Red:

http://www.legitreviews.com/article/2092/4/
 

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Probably the reason it is not discussed more is because it is rarely a problem. You can stream a lot of 2-4MB/s videos to or from a single HDD. There is certainly plenty of evidence that a DVR can record multiple streams while simultaneously playing back one stream -- they have been doing it for years now. Of course, that is not exactly what you are asking here, since you are interested in multiple simultaneous reads. But simultaneous writes plus one simultaneous read is a similar workload, I think.


The only time it becomes a problem is when you are simultaneously doing a very high throughput read or write to the drive (such as Nev's example of streaming a movie while simultaneously trying to do a full-speed, probably 100MB/s, write to the HDD)
 

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I've streamed 4 blurays (30GB MKVs) in my home from my server to HTPCs, desktops and laptops and there wasn't any issue as long as I plugged laptop into LAN cable.


At first only the laptop stuttered but I realized that was wireless limits. I can stream lower bit rate stuff wireless but full blown 1080p I can't.


My desktop (Asus deluxe mobo with Intel LAN) to my server (Intel NIC card) with cat6 cable (short run) and a cheap Asus gigabit switch consistently give me 110MB/sec transfers to or from.


I'm nearly certain in my personal set up my network speed is the limiting factor or bottleneck. My HTPC , desktop and server should perform beyond the network limit in other areas.


My server is almost exclusively 3TB Seagate drives that easily outperform my network speed. I've tried to maximize my performance with an Intel NIC but honestly I got pretty great performance with the crappy LAN built into my AsRock z77 motherboards (both HTPC and server). I'm not sure the intel NIC helps much.


I don't own enough machines to stream more than 4 at a time but I can say with absolute certainty that I can do 4 at once without issue.


If your running a NAS box or Unraid set up or your running slower 2TB WD green drives then its likely you'll have a bottle neck much lower than my Flexraid server. I could see possibly four streams being an issue. I can't imagine two or three at once wouldn't work though.
 

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Quote:
Originally Posted by Mfusick  /t/1472804/how-many-movies-can-be-streamed-from-one-hdd-simultaneously#post_23322351


I've streamed 4 blurays (30GB MKVs) in my home from my server to HTPCs, desktops and laptops and there wasn't any issue as long as I plugged laptop into LAN cable.


At first only the laptop stuttered but I realized that was wireless limits. I can stream lower bit rate stuff wireless but full blown 1080p I can't.


My desktop (Asus deluxe mobo with Intel LAN) to my server (Intel NIC card) with cat6 cable (short run) and a cheap Asus gigabit switch consistently give me 110MB/sec transfers to or from.


I'm nearly certain in my personal set up my network speed is the limiting factor or bottleneck. My HTPC , desktop and server should perform beyond the network limit in other areas.


My server is almost exclusively 3TB Seagate drives that easily outperform my network speed. I've tried to maximize my performance with an Intel NIC but honestly I got pretty great performance with the crappy LAN built into my AsRock z77 motherboards (both HTPC and server). I'm not sure the intel NIC helps much.


I don't own enough machines to stream more than 4 at a time but I can say with absolute certainty that I can do 4 at once without issue.


If your running a NAS box or Unraid set up or your running slower 2TB WD green drives then its likely you'll have a bottle neck much lower than my Flexraid server. I could see possibly four streams being an issue. I can't imagine two or three at once wouldn't work though.

Are you running a Dual Band Wireless Network in your system?


This has been an ongoing issue for me as well. Using XBMC I transitioned to NFS from SMB and there was a boost in performance for 1080p playback via wifi to my Raspberry Pi and my Laptop. The Laptop is running on a 5ghz Band and plays movies without a hitch. My Raspberry Pi for now is working on the 2.4ghz and it will play lower bit movies, even the Warner Bros. Discs that have Lossless audio but encoded at 1080p using M2TS as the container. Only movies with HD Audio are a problem streaming to my Raspberry Pi for now. I plan to get an Airport Express with Dual Bands to fix this issue. I have an older APE and that alone improved 1080p playback to the RP with minimal pauses during playback, compared to a wireless N USB Adapter physically connected to the RP.
 

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Just for fun, I started playing a bunch of my MKV blu-ray rips with VLC. They were all playing from the same HDD (a 4TB Hitachi 5400rpm) over a Gbit ethernet connection from my linux server (samba) to my Windows computer. I went up to nine and did not notice any obvious playback issues, but it is somewhat difficult to tell. The sound was a horrendous din, but I did spend a few seconds watching the video of each and I did not see any obvious jumps or freezes. So probably I could have kept going, but nine was enough fun for me.

 

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I used to torture test my DVD drives by loading a DVD and opening multiple instances of VLC each playing a different chapter. I had an old Samsung that could stream 4 chapters at once. Boy was the drive noisy though!
 

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You can use a cheap SSD drive for caching to increase the number of streams.
 

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Quote:
Originally Posted by itznfb  /t/1472804/how-many-movies-can-be-streamed-from-one-hdd-simultaneously/0_100#post_23326292


You can use a cheap SSD drive for caching to increase the number of streams.

No, you cannot. At least, not unless you play the same 6 or 7 movies over and over again, and no others.
 

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Quote:
Originally Posted by jim2100  /t/1472804/how-many-movies-can-be-streamed-from-one-hdd-simultaneously#post_23326303


No, you cannot. At least, not unless you play the same 6 or 7 movies over and over again, and no others.

Why can't you? Stream a video file is pretty much the most predictive IO possible. Plus there are plenty of software options to further optimize that caching. None free that I've found though. SRT is perfectly capable though.
 
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