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[Manfred]

Hi,

I am a little bit confused about the memory playback in MC 19.

I have all my music stored in  FLAC format. I have some albums in 24 bit 192 kHz having FLAC files with size of ~600 MB. All my music is stored on a 2 TB WD 0748 USB 3.0 drive connected to a PC with USB 2.0 interfaces. Cable is USB 3.0. MC 19 streams the file over Power LAN using WASAPI mode to my amplifier and DAC.  MC 19 and my new amp and DAC are the best sounding devices I ever had in my long Hifi life  I also have JRemote.

1. Do I understand memory playback in MC19 correct (the FLAC file is completely loaded in memory if the file size is less than 1 GB. )?

Doing some math: USB 2.0 interface bandwidth is 480 Mbit/sec. So the time to transfer the file from the disk in memory should be 600 MB/[(480/8) MB/sec] = 10 sec if one assumes that bandwidth utilisation is 100%, which should not be true in reality.

What confuses me, is that playing the file starts after 1-3 sec and not after 10 sec as calculated!!!

2. So what's wrong?

3. I also want to buy a new HTPC for my living room, so would it be better to use an internal disk with 6 Gb/sec SATA 6G or USB 3.0 with 5 Mb instead of using Ethernet with 1 Gb/sec?

1Gb Ethernet whould lead to a time of  600 MB/[(1024/8) MB/sec] = 4,7 sec to load the file in memory. Also assuming 100% utilisation for simplicity.

4. Have I understand that correct?

Thank you very much for your help!

[rayooo]

Regarding play from memory... I initially assumed the new MC 19 mem play in fact decoded to cache  the entire track prior to playback starting.   As I now understand it, MC decodes and caches some portion of the track and play begins...and decoding continues in background during playback.... At least I think this is the case.  

OBTW, I've used wired GIG-E to my primary MC player for years now with media (Audio only in my case) stored onSynology 5 bay - older model version whatever it's called.
It continues to work extremely well.

[mwillems]

Regarding play from memory... I initially assumed the new MC 19 mem play in fact decoded to cache  the entire track prior to playback starting.   As I now understand it, MC decodes and caches some portion of the track and play begins...and decoding continues in background during playback.... At least I think this is the case. 

Check out the first post in this thread:

http://yabb.jriver.com/interact/index.php?topic=81982.0

For most tracks it decodes the entire track into memory as quickly as it can.

The cut off is if the decoded file would be larger than 1GB; then JRiver decodes 1 GB worth,and then another 1 GB  block later.  This is because there are limits to the amount of RAM JRiver can access (as a 32-bit program) and to prevent some extremely large files from filling the entire system memory (as some DSD files might decompress larger than most modern system's available memory).

I'm not sure how to address the I/O issue; you're right, it shouldn't ordinarily be able to start that fast, unless it starts playing before everything is loaded and decoded.  An easy test would be to watch your system monitor as you hit play and see if there's disk and CPU usage after the music starts playing, and if so, when it stops.

[rayooo]

Check out the first post in this thread:

http://yabb.jriver.com/interact/index.php?topic=81982.0

For most tracks it decodes the entire track into memory as quickly as it can.

The cut off is if the decoded file would be larger than 1GB; then JRiver decodes 1 GB worth,and then another 1 GB  block later.  This is because there are limits to the amount of RAM JRiver can access (as a 32-bit program) and to prevent some extremely large files from filling the entire system memory (as some DSD files might decompress larger than most modern system's available memory).

I'm not sure how to address the I/O issue; you're right, it shouldn't ordinarily be able to start that fast, unless it starts playing before everything is loaded and decoded.  An easy test would be to watch your system monitor as you hit play and see if there's disk and CPU usage after the music starts playing, and if so, when it stops.

check reply #49 from that above mentioned thread

[mwillems]

check reply #49 from that above mentioned thread

Got it, but how quickly does that happen?  I may do some system monitor tests of my own later today and see (i.e. is it really done as quickly as possible, or does it keep going throughout the track).

[rayooo]

Got it, but how quickly does that happen?  I may do some system monitor tests of my own later today and see (i.e. is it really done as quickly as possible, or does it keep going throughout the track).

Good question, I wish I knew. I've tried to read-between-the-lines on some of these details, but I always end up getting confused by seemingly different answers.

In my case, even with DSD, the initial decode to play, seems to happen in as you mention a second, or possibly up to three seconds.
My presumption now is, that assuming of course the track in question is less than the 1 GB limit, that the entire decode/cache would be finished in the next 10 seconds or so, but I'm guessing.   I wish someone would explain It for dummies like me, but, I know the MC folks have more to do than do "MC internals for Dummies" every day of the week.

[Manfred]

I have done some measurements with the following albums both 24 bit 192 kHz:

Wagner, Richard: de Vlieger: Tristan & Isolde by Hagen Philharmonic Orchestra (Album 1)
Berlioz: Symphonie Fantastique by Scottish Chambre Orchestra (Album 2)

t (sec)   FLAC file size      MB/sec   Album/Track
3,11   353 MB                      113         1 / 1
2,19   594 MB                      190         1 / 3
3,37   261 MB                        77         1 / 4
2,66   544 MB                      204         2 / 1
2,51   569 MB                      226         2 / 3

t is the time after music starts playing after hitting the play button in mc19. Time is measured through my iPhone with an uncertainty of 10-20% (one must hit the MC19 button and the start button for the clock simultanously)

What I found strange is that the USB interface of the PC is USB 2.0 with max 60 MB/sec.; the WD MyPassport 2 TB has an USB 3.0 interface and cable.

I definitely expected lower MB/sec!!!! ? Why???

Memory size increases e.g. for track 3 album 1 from 1.94 GB to 2,56-2,59 GB (after some time), so MC 19 has loaded the file in memory and starts decoding. CPU is between 10% - 44% peak,  Core(TM)2 6600 with 6 GB RAM and an SSD for Windows 7 64 bit.

The WD MYPassport 2 TB disk is formatted with a higher NTFS block size as the default (4k) – media files are typical larger than 4k .-)
Bytes per sector: 512
Bytes per cluster 65536
File Record size: 1024 bytes
NTFS Version 3.01

As I understand  reply #49 correctly : Playback starts before the full track is loaded into memory , but only if the file is > 1GB? So thats ok from my understanding.

My core question is, is it better to use an internal disk with SATA III interface with a SATA drive of 3-4 TB or an USB 3.0 external disk like my 2 TB one, if one wants to use memory play with short starting times, if one has a lot of large FLAC files ~500 MB?

A remote disk of POWER LAN with ~ 200-300 Mbit/sec has a from my point of view a to low bandwidth to use a remote disk in my  working room.
SSD would be best to reduce stating times but its very expensive 2 TB of SSD cost ~1000€ in Germany.

[6233638]

Answered here: http://yabb.jriver.com/interact/index.php?topic=81982.msg576537#msg576537