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In Reply to: RE: Any failure of hard disks in your NAS ? posted by Tony Lauck on November 19, 2014 at 09:29:16
Hi and thanks a lot for the very informative reply
I understand that the issue is very complex with many variables
Lately i have slimmed down the SW in the PC so that now i have only a small SSD with the programs still in the pc and all the AV files in a NAS
I like the NAS solution because with the router i can access the files from everywhere in the house.
I think that your point about the heat in particular is very important
I have already noticed how low is the consumption of my 2 bays Synology
and the disk (one for now) stays quite cold (and also nicely silent)
To end i take the liberty to attach again the link to the review
Thanks a lot again
Kind regards,
bg
Edits: 11/19/14 11/19/14 11/19/14Follow Ups:
I suggest connecting an external drive directly to your PC and copying a few test files to it. Or, you can copy a few test files to your SSD. Then try comparing the sound quality you get when playing direct from the PC with that when you play from the NAS. Many people have found that sound quality is better when playing off local drives rather than over an Ethernet. If you look at total CPU utilization you will see that the network approach uses more processing in your PC.
I take this one step further and play out of a RAM disk on my PC. So there isn't even any disk I/O at all when listening to music. There is a slight inconvenience for this, however, because it takes a few seconds to convert a file on disk from FLAC to WAV and store the WAV in the RAM disk before I can play an album.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Hi and sorry to disturb again
If i understand well a Ram disk inserted in the PCI (which one ?) slot reduce the I/O operations ?
Why not go further and increase the amount of the real RAM ?
some PC can use up to 16 GB (if not more)
Is it possible to do so ?
There is nothing like a speedy RAM i think when direct access is required
Thanks a lotP.S. i think this new family of SSD will make you change your take on SSD
http://www.maximumpc.com/ocz_trots_out_vertex_460a_ssd_series_using_toshiba_a19_nand_flash_2014
around 0.5 Gbps reading speed on a SATA 6Gbps channel (wow !)
allowed by the new 19nm Nand chip by Toshiba, i guess a great achievement indeedor better still ... wait a little bit for this ... SATA Express (16 Gbps !)
http://www.legitreviews.com/what-is-sata-express-and-why-it-matters_140093
the "PC world" is the only one that is getting better and better ... unfortunately
Kind regards,
bg
Edits: 11/19/14 11/20/14
A RAM disk is not any separate physical component. It's just a device driver (software) that grabs a block of RAM at system boot, removing it from other use and creating the appearance that there's a separate disk device and file system.
For my Windows system I am using an older (free 4 GB) version of the software linked below. This was free, but I don't see a free version on the web page today. For Linux systems ram disk software is available for all distributions and can be installed and activated for free (assuming necessary Linux knowledge).
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Hi and thanks a lot now i understand better
Interesting solution indeed
I guess this is the most direct way to read data without possible bottleneck
A very high end solution
I wonder if the benefits would be evident also on an average playback system
I have to try of course
Thanks again.
Kind regards,
bg
First of all, for 2-ch audio playback there is no bottleneck at all within any modern PC or Mac. Audio playback is not resource, disk, or I/O intensive. It just isn't. You can use the slowest and very quiet 5400rpm 2.5" laptop drives which will be more than sufficient.Some folks use RAM disk so the music is pre-loaded and played out of RAM so the spinning disk drive is not being accessed while the music is playing. One theory is that if the disk heads are moving to access the music file, you might hear it.... or just the fact that there's a signal (noise) from the disk I/O, that might be an issue. All highly debatable stuff in terms of whether it matters or not, and the only way to determine any benefit is to try for yourself.
The benefit of using a RAM disk with SSD is also debatable. The SSD has no moving parts so who cares if it's being directly accessed while playing music. Some will say that the mere fact that it is being accessed might produce noise due to the I/O to the SSD. Again, in the weeds audiophile stuff. Try for yourself and see if it matters.
And finally, many music players like Audirvana Plus, Pure Music, and others incorporate their own form of RAM disk often called 'memory play'. Again, music is preloaded into your system RAM before playback so there are no disk or SSD I/O operations taking place while playing music.
As for experimenting with RAM disk, Tony had some comments on how to do it in Windows. Here's how on a Mac with no special additional software or drivers. Just some command line stuff in the Terminal window:
Create experimental 1GB RAM DISK on Mac
Disk Utility shows the 1GB RAMDISK
Edits: 11/20/14
I went to using a RAM disk because it bypassed using spinning rust. I was able to hear the noise made by the spinning rust while seeking. Also, I wanted to do the conversion from FLAC to WAV off line. If I had an SSD to use as a cache for music files then perhaps I would have done it differently. However, I don't think this is a good idea, as it creates a lot of write traffic to the SSD and may impact wear.
If your favorite player uses memory storage and this is done correctly it will be better to load the play list into the player's memory. This avoids processing the WAV file RIFF headers during real-time music playback. However, this is only feasible on a 64 bit operating system with lots of RAM if one has long playlists of high-res files. With this approach it is possible to completely suspend the operating system if the DMA controller for the audio output has enough addressing/counting capability.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Tony, when you do your FLAC to WAV conversion is that done 'on the fly' just prior to each music file being played? Or is it more of a batch process? I'm not sure I understand but it would make sense not perform a lot of unnecessary writes to the SSD, and doing your conversions in RAM will be lightning fast.
In most music server setups SSD write endurance isn't a problem because well over 90% of the operations to SSD will be reads. Besides, the endurance of MLC SSDs have gone up significantly just in the past couple years. So much so that the lines between MLC and SLC have blurred. Many enterprise class storage systems that used SLC SSDs have recently gone to MLC. SLC is already rare, very expensive, and likely to become unavailable in short order..... because it is too expensive and no longer cost effective.
I work as follows when playing FLAC files.
1. I open the folder containing the tracks of an album.
2. I select the tracks that I wish to play. (Typically several tracks, e.g. four tracks for four movements of a symphony.)
3. I right click on the selected tracks and Dbpoweramp converter converts these to WAV and stores them in the RAM disk.
4. I open HQPlayer and tell it to pick up all the tracks in the RAM disk.
5. I click play.
6. When done I close HQPlayer.
7. I clear out the RAM disk.
It would not be practical to do the conversion prior to each track as this would change the delay between tracks and add glitches to albums that were made to be played "gapless". The downside is that long play lists (e.g. Bach's St. Matthew Passion) can exhaust the size of the RAM disk that I have set up if they are hires. If this happened often I would upgrade the RAM disk from 4 GB to 8 GB, but then I would need to add more RAM to my computer, which presently has only 12 GB of RAM.
I have no idea whether or not SSDs have become reliable. They were not. As far as I can tell micro SD cards are still unreliable -- it's been only about two months since I lost data on one that was being used to do compiles and operating system updates on a Raspberry Pi. I recently got a 120 GB SSD that I am using on an Atom based NUC as a Linux server. This will get a pretty good thrashing due to data base updates. I will be pleasantly surprised if this device makes it through a year.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Hi Mr. Collins !
thanks a lot for the very helpful advice as always
The idea of direct memory access is very sane on principle
I will look for a Windows audio player SW with the Ram disk feature
As a second option i like very much SSD, that are getting bigger and faster any day
I have read something about the new NAND chips and i am impressed
They allow for 0.5 Gbit/s read and write speed
Transfer speeds almost at RAM levels and also " ... up to 95K read IOPS [input/output operations per second] ! ... "
Ok ... there will be still some I/O but this is very fast and not very expensive i hope.
Thanks a lot again.
Kind regards,
bg
Edits: 11/20/14 11/20/14
Hi and thanks for the advice
I have been able to connect the main pc with an ethernet cable to the router (no wifi i mean).
Only the secondary system is through wifi in the bedroom (just background listening when i write with the pc)
I am not an expert but i guess your solution is indeed the ultimate and the best one
I do not know if tests with HD video files can tell something about the quality of the playback system.
For now i do not get any drop out or problem
My idea is to add a 2nd SSD and to read the files from that
I read 3 Gb/s on the SSD . It's a lot indeed.
I like the SSD so much and i think that something spectacular is going to happenhttp://www.zdnet.com/toshiba-launches-smallest-embedded-nand-flash-products-to-date-7000034281/
a 128 GB NAND chip of about 0.5"x0.5" size (!)
http://cdn-static.zdnet.com/i/r/story/70/00/034281/screen-shot-2014-10-02-at-10-03-51-458x330.png?hash=BGAvMJZ2MG&upscale=1
Thanks again.
Kind regards,
bg
Edits: 11/19/14 11/19/14 11/19/14 11/19/14
They will fail one day.
Hopefully your active HD and your backup will not fail on the same day.
I once forked out an additional 50,- for a true 7x24 HD for my NAS.
It crapped out after 2 years.
Ordered a new “normal” one, restored from my second NAS and within 2 weeks the other NAS had a HD failure as well.
What you need is a good so really paranoid backup system
The Well Tempered Computer
Hi and yes you are right of course
If safety of data is paramount a serious back-up solution is the way.
Still i was a little surprised to see such low figures
But the stress for the HD mechanisms working 24/7 must be really huge
Poor disks ...
Thanks a lot for your advice.
Kind regards,
bg
I appreciate the fact that network traffic takes some CPU power, but I don't share Tony's concern about network processing load. Here's the CPU history for my i7-860 based server uncompressing FLAC and sending two independent music streams to Touch players, one via ethernet and the other via Wi-Fi:
Every once in a while the total will *spike* to 1%. Now, if you really want to exercise your processor, use Handbrake to convert a video file for use on a Mac product. :)
Hi and thanks a lot ! very interesting
Really impressive the cpu work for video tasks ...
I wonder if, as an extension, High Definition video files can be used to assess the quality of a streaming
I mean, if the streaming with this heavy files is very good streaming of audio should not be an issue.
Am i right ?
I have to find some of these very big files to test my little nas system
and in general all the peripherals.
Thanks again.
Kind regards,
bg
I mean, if the streaming with this heavy files is very good streaming of audio should not be an issue.
Am i right ?
Seems resonable to me. I played a hi-def video on my laptop that lives on my server. While network utilization increased, CPU usage bumped 1% just a bit more frequently. Much like Abe's test simultaneously downloading three large files. I think the underlying question has to do with the CPU used. My previous 2002 circa Pentium could be slammed by most any application. The i7 actually has similar drystone and whetstone performance to the classic Cray 2 supercomputer. BTW, if you're interested in relative CPU benchmarks, I find this site to be pretty useful.
As for Handbrake , I don't have any other application that comes even close to fully utilizing all CPU cores simultaneously. Not Flight Simulator. Not Starry Night Pro that has to render the universe. The writers must have spent some time optimizing the code to get that kind of efficiency. It sure knows how to crunch numbers!
Hi and thanks a lot again for the very valuable advice
I will test my cheap LAN with some HD video files soon.
" The i7 actually has similar drystone and whetstone performance to the classic Cray 2 supercomputer "
wow ! this is impressive and speaks a lot about the technology improvements. Amazing i did not know this.
Thanks again.
Kind regards,
bg
I tend to agree with you when talking about modern computers.
Unless you're servicing a lot network traffic, which is hardly the case when streaming music or video, or downloading a couple files, the network load is going to be very light on system resources.
Several years ago we began to see TCP Offload Engines (TOE) on server class NICs in high traffic environments. It wasn't uncommon to pay several hundred dollars for these NICs which freed up CPU resources under heavy network load. I'm not sure if TOE has trickled down to onboard chips and ports found on typical PC motherboards.
Obviously a low powered low-end system will be more impacted by network traffic so unless your system is one of those stripped down minimalist boxes I don't see a problem.
In any case, I'm downloading a few huge HD video files on my Mac and it appears they hardly put a dent in my system resources.
Downloading 3 Movies
System Resources Hardly Dented by the simultaneous downloads
The load isn't going to break the CPU or cause stuttering. However the associated processing activity may degrade sound quality if the periodic noise generated by protocol processing and data buffer movement reaches analog equipment in the DAC and amplifiers. There are probably ways to measure this activity, but you will have to listen to sound quality to tell the extent that it matters. This situation is roughly similar to what happens when playing FLAC vs. playing WAV files.
You may also want to look at the Processes tab, including system processes.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
if the periodic noise generated by protocol processing and data buffer movement reaches analog equipment in the DAC and amplifiers.Understood. If you want to get really granular and run resource manager, one finds that the total system load is runs decimal fractions of one percent - which gets rounded up to one.
I certainly appreciate the need for system and power supply isolation. I run two dedicated 20A lines to the main system and employ shielded power cords with every component. The server is located on a different floor and on a completely separate breaker box than the system upstairs.I have two pretty decent systems and find they provide better resolution than the CDPs the Touch players/DACs replaced. System details available if you click my moniker.
Edits: 11/19/14
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