Memory playback
A claim made quit often in audiophile forums is that reducing electrical
activity inside the PC improves sound quality.
Memory playback (reading the file from the HD and store it in memory before
playback starts) is one of the tweaks.
This reduces HD access during playback
Reduces? Yes, it won’t prevent other processes to access the HD.
The purist will of course require a HD spin-down too….
If you play from a NAS there is no access from the local HD by JRiver as all data fetched from the NAS is already stored in memory.
Issue with the "Playing files from memory" optionOnce you have memory play enabled and press play, MC starts to play. It won’t wait until the track is fully loaded.
Using MC 14.0.155 on Win7
Configured MC to play from memory
Started playing a track, 288 Mb WMAL, close to 1 hour of music.
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| Before I hit play, I waited until all I/O inherent to system startup had finished | After an initial spike, no visible I/O except for an occasional Win7 process | After about 9 minutes, all of a sudden a constant stream of disk I/O about 90.000 B/sec starts. This continues for the duration of the track |
Plenty of memory free.
According to the forum, memory play is capped at 256 MB.
From build 17.0.47 on:
4. NEW: From memory audio playback will use up to 1GB instead of 256MB (after 256MB it checks against available memory to avoid using swap).
If this is the case, I expect some I/O at the end of the track, not after 9 minutes
As Matt says: The cap is 256MB ahead of the current file position.
Explains a lot.
Ok, let’s try something smaller
Playing a 45 MB file,
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Memory play off Notice the small spikes in the Disk graph |
Memory play on Zero disk access. More hard faults from Memory |
Playing a 250 MB WMAL file
This fits in the 256 MB limit
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Memory playback on There is a constant stream of 50000 B/sec. Very much like reading straight from the HD. |
Memory playback off, same file A long time no disk access at all! Then the I/O kicks in Looks like it is playing the cached file. |
Restarted MC 14, memory playback off. Now it plays from HD straight away |
The dialog says that the changes take effect once playback is stopped.
In case of memory playback it looks like you have to restart JRMC..
From a audiophile point of view:
- Amount of allocated memory is to low. Should at least be able to contain
an entire CD (for those who rip a CD to single file with cue-sheet). Not
to mention those who upsample redbook audio off line to e.g. 24/176.
Preferably this should be user configurable. If you run Win64 you can use memory > 4 Gb - Decoding should be done when loading the track. This will minimize CPU
during playback.
Differences in sound quality between WAV and FLAC are often explained by the difference in CPU needed. This feature will effectively eliminate this. - Start of the playback should be user configurable (wait until song fully
loaded or start right away).
In other words, if you go the audiophile way, go all the way.
A nice test: MC starts playback immediately. At a certain moment the song is fully loaded and I/O stops. This is the moment you should hear a change in sound quality. Good luck!
One think is sure, If the heads of your HD are noisy (acoustically) this option sure make a difference!