Hard drives can directly over-write a sector, but NAND-Flash SSDs cannot overwrite a page. The entire block must be erased, and then the page can be re-used. If there is other data in the block's other pages, it must be moved to a different block, before the erase.
A common block size is 512KiB, and a common page size is 4KiB. So if you write 4KiB of data, and that write needs to be done to a used block, that means at least 508 KiB of extra writes have to occur first; that's an inflation rate of 127x. You might be able to write 2x or 3x as fast as you can to your 10,000 rpm hard drive, but you may also end up writing 127x more data. If you are using your drive for small files, write amplification will hurt you in the long run.
32 pages of 512+16 bytes each for a block size of 16 KiB 64 pages of 2,048+64 bytes each for a block size of 128 KiB 64 pages of 4,096+128 bytes each for a block size of 256 KiB 128 pages of 4,096+128 bytes each for a block size of 512 KiB
(Source: http://en.wikipedia.org/wiki/Flash_memory)
Long-Term Storage.
Magnetic storage mediums often retain data longer when un-powered, so hard drives are better for long term archiving than NAND-Flash SSDs.
When stored offline (un-powered in shelf) in long term, the magnetic medium of HDD retains data significantly longer than flash memory used in SSDs.
(Source: http://en.wikipedia.org/wiki/Solid-state_drive)
Limited lifespan.
A hard drive can be re-written to until the drive breaks from wear and tear, but a NAND-Flash SSD can only reuse its pages a certain number of times. The number varies, but let's say it's 5000 times: if you reuse that page one time per day it will take over 13 years to wear out the page. This is on par with a hard drive's lifespan but that's true only without factoring in write amplification. When the number is being halved or quartered it suddenly doesn't seem so big.
MLC NAND flash is typically rated at about 5–10 k cycles for medium-capacity applications (Samsung K9G8G08U0M) and 1–3 k cycles for high-capacity applications
(Source: http://en.wikipedia.org/wiki/Flash_memory)
Power Failure.
NAND-Flash drives don't do well with power-failures.
Bit corruption hit three devices; three had shorn writes; eight had serializability errors; one device lost one third of its data; and one SSD bricked.
(Source: http://www.zdnet.com/how-ssd-power-fault...000011979/)
Read Limits.
You can only read data from a cell a certain number of times between erases before other cells in that block have their data damaged. To avoid this, the drive will automatically move data if the read threshold is reached. However, this contributes to write amplification. This likely won't be a problem for most home users because the read limit is very high, but for hosting websites that get high traffic it could have an impact.
If reading continually from one cell, that cell will not fail but rather one of the surrounding cells on a subsequent read. To avoid the read disturb problem the flash controller will typically count the total number of reads to a block since the last erase
(Source: http://en.wikipedia.org/wiki/Flash_memory)
Got the opportunity to test and possibly buy a second hand Panansonic TX-P42X60B Plasma this weekend. Price is good and I've been looking for something like this mainly for SD content, Cable TV and 720p video files.
Just wondering if there's anything in particular I should look out for? (Having never owned a Plasma!)
I'm going to take a USB stick with various things on it along with some test pattern JPG's (100% white, 100% black, 5% grey)
I'm interested to know what 1080i content will look like downscaled on 720p TV. I've also read the screen can be quite reflective so I'll keep an eye on that.
During the last weeks, I thought a lot about upgrading my desktop PC... what to do? Just add a better GPU? An SSD? More RAM? Or change the whole system?
Read on, because I learned something meanwhile, that may be of some help for someone; waiting for your opinions and advices as usual!
Computer for restorations - a simple FAQ
Which computer for restoration purposes?
My advice is to go with a desktop computer, leaving a laptop for other uses.
Best option would be to make a custom built one (or buy a used one that will suite your need); also, some pre-built rigs could always do, but they have limited hardware combinations, or, with the right one, price is usually higher.
Used or brand new?
Well, nice question! If you are "rich" go for a brand new one; but if you aren't (like me), you could spend something like 20/30% less with "fresh" hardware, while a lot less with older ones. Sure, new hardware has warranty, but "fresh" one has it too - and some hardware has like 5-years warranty!
Workstation or gaming PC?
I do not play games on PC (actually, last time I played with my old PS3 was... few years ago! ), so I do not "see" gaming PC with gamer's eyes; from a restoration point of view, powerful gaming PCs have great potential, and often are great as restoration PCs; sometimes workstations are good, too, but they usually cost a lot more, often with lower specs or bang for the bucks - your mileage may vary, of course!
Which CPU?
So difficult to say! Let's start... I'd avoid non-Zen AMDs, and stay ONLY on ThreadRippers and Ryzens (possibly 7); for Intel, I'd go only with i7 and i9 (and Xeon comparable ones), possibly the K and X versions, giving maybe some chance to the best i5, avoiding at all i3 and others.
Do I need latest models?
If you have to start from scratch, I'd go for the newest model you can afford; yet, the increment in speed between two generations is usually quite limited (few percentage points); for AMD, Ryzen and ThreadRippers are quite new, so there is not too much to choose from; Intel, at the contrary, made a lot of different families over the years... I'd go at least for a 4th generation (Haswell/Devil Canyon) and not older, even if there are some older models still quite powerful, but they are frankly dated, as related hardware (MBs, RAMs etc.) - so, unless they are VERY cheap, and you do not expect miracles, you *may* take them in consideration - me, not!
How many cores?
I guess four is the bare minimum nowadays; no need for 28/32 cores at all IMHO, because it seems speed after 14/16 cores would not increase.
Frequency?
The higher the better? Yes and no... yes (usually) if you compare same family; also, keep in mind turbo boost, and possible overclocking - nowadays many motherboards and BIOS allow moderate OC automatically without big problems.
Overclock?
Apart the allowed one that I talked before, there is always the possibility to get even higher speed with tailored settings - but you must know what you are doing! Plus, there is always the "silicon lottery", where a small percentage of a given model could raise higher frequency than all the others; difficult is to spot the "right" ones!
Delid? Direct die?
Only for the most experienced users - or, if you find out a used one; but be careful, because they are usually very used ones, so they could die in a short time... you were warned!
Air coolers? Liquid?
Mmh... this will start a bloody wars between the followers of one or the other party... I can say that it's always better to replace the stock cooler, to get lower temperature - in particular, thinking that an encoding could take many hours, if not days... usually, air coolers are more than good for CPUs not overclocked, while most of the times high overclocks demand liquid coolers - but not always, so... it's up to you!
Motherboards?
Of course a compatible one! Jokes apart, there are also so many models that is impossible to say which is the best... take a look at the features first, connections etc. - I also note the construction and durability, material... do note that there are some "transitional" models, that got both new and old features; these could be useful if you have some older hardware that could be not compatible with the "all new" models.
Which GPU?
Before, I thought a powerful GPU would not be useful... well, I was WRONG! Yes, a powerful CPU is always needed, yet to get the best from some software (I think in particular to DaVinci Resolve, that uses GPU in a very heavy way), it's better to get the best GPU you can!
Nvidia, I'd go with any RTX, and best GTX (not under 1060 IMHO), while best Quadro may be useful, but very expensive; for AMD, I'd use only Vegas and RX 570/580. Of course, lower models could be enough, but as usual, the lower, the slower, so... and, try to get models with most memory!
RTX or GTX? Ti or non-Ti? Founders, or not?
RTX may have some interesting features for restoration purposes, but I think they are not yet developed (or quite difficult to use for the "normal" users); so, unless you know how to use Tensor cores, Python, Pytorch and the like, probably a "normal" GTX would do. Ti are better - more memory, faster - so, again, if you can, go for it! Founders... I'd go with the non-Founders, as usually they have better cooling and overclock capability.
Single GPU? Double, triple, quadruple?
My opinion (and not only mine) is, get the best single GPU you can afford; because a double GPU will not (usually) means double speed... also, take in account that few softwares could benefit from multiple GPUs - DaVinci Resolve is one of them, but NOT the free edition, beware!
What's about RAM?
As usual, the fastest the better, the more the merrier! Minimum today should be 16GB for 2K, better to get 32GB for 4K and 64GB for 6K/8K; usually more than 64GB is not useful for the moment. Also, take a look at what version your motherboard support - it's useless to buy 3200MHz where your MB will support only 2400MHz; choose the right ones (DDR-3 or DDR-4), better a pair than single bank - or better four instead two for the quad channel chips like ThreadRipper.
And HDDs?
Old hard disk drives will be surely replaced by SSDs in the future, but for now the cost-per-gigabyte of a mechanical HDD is still a lot better, so... use an SSD (better M.2, U.2 or PCI-e) for OS; this does not need to be huge, but also think about how many software you think to get; for someone that uses few softwares like me, a 120GB should do, but I'd go with at least 240GB.
I'd add a second SSD for daily use (conversions, encoding, temp files); SATA would do for 2K, but fastest M.2, U.2 or PCI-e are better for 4K, and I'd say mandatory for 6k/8k. Big HDD(s) should be used as long term storage, because, even if SSDs are usually more durable than HDDs, they could fail without notice, while often (sometimes?) mechanical HDDs start to make strange noises before dying... and, remember to make backups (at least, of the most important and irreplaceable files.
And PSUs (power supply units)?
This is often underestimated, but it's VERY important! First, use a wattage calculator, put the data of the hardware you would like to get, and then buy at least a PSU with some watts more - a lot more if you plan to add "hungry" hardware, like a plethora of HDDs (like me) or a second (third? fourth?) GPU!
Modular or not modular?
Well, once I thought that any modular PSU could be replaced with any other model from any other brand.. WRONG! Almost any brand use its own kind of cables - or, if the same, they are wired differently... so, a modular one could be useful to get more order in the cable management, or to be replaced easily with the same model (or another from the same brand, probably); yet, any track has an ampere limit, and this *may* be problematic in some (few?) cases... so, do not discard non-modular ones!
Which PSU model/brand?
Go only with the best, known one... a PSU tier list is useful; try to get one in the first tiers, avoiding the last ones - as usual, try to get the best you can, and DO NOT spare money on this, trust me!
And case?
Case is up to you, of course; yet, I strongly suggest to get a big one, with quite some fans, to let enough air to circulate - it will be hot inside, granted! - capable to cool well CPU, GPU, MB and all; also, take in account GPU lenght, CPU cooler height, room for HDDs, optical drives, added PCI-e cards etc.
Keyboard, mouse, other things?
Again, keyboard and mouse are up to you; just choose something durable, you will use them A LOT!
Other things that you may need are eventual audio and video capture cards - a must have if you want to capture VHS and Laserdiscs, but not only... vynil, anyone?
Last words
My advice is to get the best you can, trying to not spare money now, because you surely have to spend (more) later; take your time, do not rush, study, make your homeworks; think also that this computer will hopely not be used only for restorations, but also to surf the net, watch movies, listen to music, and, why not, play games - confess!
Say for example, you use an external hardware effect (like a Surround decoder), but your soundcard has a lot of noise. Well, just create multiple recordings and then let it run through audiomedian. For each single audio sample, the Median will be calculated and written to the output file. The output file is always a 32 bit floating point WAV.
Same could probably work for capturing VHS audio tracks or analogue Laserdisc tracks, but it's important to note that the audio has to be absolutely perfectly in sync for this to work properly, otherwise you are likely to get some form of distortion/artifacts. And with perfectly, I mean sample-perfect.
Another thing I hope it might theoretically be used for is to take audio from multiple languages of a movie and use this to try and eliminate voice from the audio, to be left with only music and SFX. Though whether that can work reasonably has to be tested, as the soundmix is never 100% identical and often not 100% in sync, and even if it was, it's not clear if this would actually work. But hey, it's something to play with!
Here is the full readme for caveats, disclaimers and whatnot:
Can receive odd number of input clips, that means: 3,5,7,9,11,13, etc.
Notes:
- output file will never be overwritten, make sure it doesn't exist yet.
- It doesn't matter whether you put the -o parameter in the beginning or end, or in between
- Needs odd number of input files
- Output file is 32 bit floating point WAV, no matter the input format
- Number of channels doesn't matter
- Audio formats (bit depth/sample rate/channel number) should match across all files, otherwise undefined behavior - in other words, unpredictable. You may get a result, but it may not be clear what exactly you are getting.
- Has the normal 4GB WAV file size limit. Note that the output wav has the limit too, and it's always 32 bit per channel, so it might be bigger than your input file.
- Doesn't like every WAV file. Will sometimes refuse a WAV file for weird reasons. Try resaving it with a few different tools and see if it helps.
- Code may have bugs, I'm a noob. Use at your own risk.
- There is no progress bar, just watch the output file grow
- RAM usage should be reasonable, as it doesn't read the entire files into memory, only works on the samples it currently needs. You can combine multiple 2 GB files with this no problem.
This tool uses the NAudio library for all this stuff, with a modified SampleProvider that creates the Median.
Code may have bugs, I'm a noob. Use at your own risk.
You need .NET Framework 4 I think. Possibly 3.5 for NAudio. Not 100% sure. Check source code/project if in doubt. This project was made in VS 2017 Community Edition.
Copyright: I don't care. Do whatever you want with the parts that I made. Otherwise NAudio probably has their own license or whatever.
You need .NET Framework 4.0 and possibly 3.5. I hope you don't need any others, but feel free to let me know if that is wrong.
P.S. I can not guarantee that this is mathematically/scientifically sound or whatever, as audio is a complicated subject. So in doubt, listen to your ears.
Edit: I tested this with a recording done through my Dolby SDU4. Unfortunately the source noise level was already so high that not much change is noticeable, but it managed to cleanly remove some small spikes (probably voltage spikes or so?) that were present in the original captures. I wouldn't have even noticed them, as they are so quiet, but now I am glad they are gone. . I did that with 3 input files.
go for a brand new one; but if you aren't (like me), you could spend something like 20/30% less with "fresh" hardware, while a lot less with older ones. Sure, new hardware has warranty, but "fresh" one has it too - and some hardware has like 5-years warranty!
), so I do not "see" gaming PC with gamer's eyes; from a restoration point of view, powerful gaming PCs have great potential, and often are great as restoration PCs; sometimes workstations are good, too, but they usually cost a lot more, often with lower specs or bang for the bucks - your mileage may vary, of course!
Minimum today should be 16GB for 2K, better to get 32GB for 4K and 64GB for 6K/8K; usually more than 64GB is not useful for the moment. Also, take a look at what version your motherboard support - it's useless to buy 3200MHz where your MB will support only 2400MHz; choose the right ones (DDR-3 or DDR-4), better a pair than single bank - or better four instead two for the quad channel chips like ThreadRipper.
