|Do NOT move your Chrome Internet Cache (or any other browser cache) off of your SSD.||okashira||6/4/10 1:50 PM|
I could not help but notice that this comment has appeared many times, in various forms, always with the same suggestion and/or comments on what users do or what someone else told them:
"Move your internet cache off of your SSD due to the constant writes causing excessive wear," or some variant of it over-stressing the SSD, reducing lifespan, or just wearing it out.
This is NOT good advice!
SSD's have an enormous amount of write endurance relative to their size. Also, the older your SSD, the more likely it has even more endurance then a newer one. If you have a newer one, it's probably larger and thus has more blocks to begin with (what I mean is, more blocks to "spread the wear," from the massive writes induced from that browsing session of yours.)
The two primary reasons why it is a GOOD idea to leave the cache (as well as indexing and your windows page file, by the way,) are:
1. SSD's are the PERFECTLY suited to a browser cache. From a performance standpoint, SSD's excel at the type of writes and reads associated with a browser cache. They will be much faster at first time caching (in that the act of them caching a new site load will not impact other concurrent and non-concurrent use of the disk relative to a hard disk) and much much faster then a hard disk at re-loading a page when compared to a hard disk. (Which, when coupled with today's fast internet connections, can often be slower at loading a page then a full fresh uncached load from the web, depending on your system and what you are doing with it at the time.) SSD Access time example: 0.08 milliseconds for a 4K read. Hard disk typical access time rate, for a cached load with other concurrent I/O's: 10ms, 20ms and up. 20ms doesn't sound like alot, but when you need to do 1000 of those reads to load somthing, they sure do. :-) 20ms vs. 0.08ms. You do the math on that one. :p The reason they are even also better at non-concurrent use of web cache and other primary storage / general use is the additional fragmentation a browser cache may introduce simply does not phase an SSD, while we all know the impacts of fragmintation on hard disks.
2. You, the typical desktop or laptop user and web surfer, should NOT be concerned with wearing out or over-stressing your SSD. The SSD's in my laptop, made from a recent 34nm process actually have much less endurance relative to older SSD's with only ~4000 write cycles available. But, mine does have more then average storage capacity at 320GB. This means that my drive(s) have a write endurance of (at least...) 1040 terabytes. That's over a petabyte. You probably won't transfer a petabyte of information ALL TOGETHER in your entire usage of the web, let alone data that's actually cached to the SSD in the next 20 YEARS. Your SSD probably has 10,000 write cycles, making it even more robust relative to its size compared to mine. Both of these numbers are only estimates and are likely VERY conservative, by the way. Also, I still have not read a single forum post / thread in any tech forum (and I have followed a lot,) of a user complaining that their SSD "wore out." This is despite the fact that SSD's have been around for... a decade? Note that there certainty have been SSD failures, but not related to "over-writing," and wearing it out. Note also that the Intel drives (the one's I run in my lappy), ignoring the whole firmware/bricking fiasco with the Gen 2 drives, have been absurdly reliable. Like 1000x that of hard disks.
Basically, what I am saying is, if you are a typical user, or even just remotely close to a typical user, and you don't need your SSD to last more then 20 years, then DON'T WORRY ABOUT WEARING THE DRIVE OUT. By taking page files, web caches off an SSD, you are not taking advantage of their primary benefit: their superior ability to handle the exact type of reads and writes that page files and web caches require.
Thanks for reading and run those SSD's into the ground! You won't regret it.
|Re: Do NOT move your Chrome Internet Cache (or any other browser cache) off of your SSD.||okashira||6/4/10 2:06 PM|
Here's another perspective. I'm going to use my setup as an example again; 320GB SSD with 4000 cycle endurance.
For a web cache even if you take the most absurd, impossible and extreme example of using browser cache: say you completely maxed out your typical 6 megabit internet connection COMPLETELY for 12 hours a day, every day. And cached 100% of that to your SSD.
1040TB of endurance.
6Mb/s = 0.72MB/s.
1040TB / 0.72MB/s = 1.52 billion seconds.
1.52 billion seconds = 35300 half days.
That's almost 97 years to wear out your SSD using the internet cache only via downloading on your broadband connection.
In reality, a heavy user is only using 10% of that on average. That results in .... nearly 1,000 years of lifetime. Do you think you will care about that $500 SSD you bought 96 years from now, let alone 1000 years? :-)
Sure, there are other factors like write amplification, but I already included a typical value (for Intel SSD's with TRIM) for that in my endurance calculation. About 1.2 overall. You'd have to come up with a pretty huge number for write amplification to bring 1000 years down to something that you might care about. :-)
|Re: Do NOT move your Chrome Internet Cache (or any other browser cache) off of your SSD.||tony786||7/22/10 7:31 PM|
Excellent explaination Okashira !!!! very good work , i've been wandering in the web for atleast a month to stumble upon this article, which is even though not technical but very well explained my burning question of could all temporary internet cache files will deteriorate my Sony vaio Z 1190's 192GB SSD drive. I can now use my ZZZ fearllesly, i was using flash usb drive for ie temp folder.
|Re: Do NOT move your Chrome Internet Cache (or any other browser cache) off of your SSD.||Tarlach||8/7/10 7:46 AM|
While this is true, it would be nicer if you elect to only use a memory cache like Firefox allows. I don't care the least about saving page data on disk. It offers no value at all when I have a lot or RAM. It's just unnecessary write activity.
|Re: Do NOT move your Chrome Internet Cache (or any other browser cache) off of your SSD.||4DGeorge||10/25/10 4:20 PM|
I have a different opinion for speeding up AND increasing the longevity of my SSD drives. And moving the temp and cache folders is DEFINITELY the only way to go.
Of course, you may say I'm cheating, given the implied intention of the discussion. ;-)
If you have greater than 4 Gig of RAM (which also implies you have a 64 bit OS) the solution is to use a RAM drive!
I have several machines (both notebooks and workstations) with 8 gig of RAM, an SSD for the OS drive, and Win7 64bit.
For each I used Dataram's free RAMDisk (http://memory.dataram.com/products-and-services/software/ramdisk) to create a 1 or 2 Gig RAM disk on each. I then moved the System and User temp folders, IE Cache, Firefox profile, and one very (very) I/O write-intensive application to this drive.
The RAM drive driver loads the file at system boot up and saves it every five minutes (configurable) as well as at shutdown.
I also compressed the folder where this image file is stored to speed up the loading at boot up (it does help).
The end result is incredibly fast web browser response, significantly faster application response when it's using the temp folders, and that very (very) I/O write-intensive application performing like a normal application. (it's a stock charting program that writes a price entry every second for every stock or FOREX currecy you're subscribed to. It results in triple the number I/O writes of ANY of the Windows 7 applications or subsystems.)
In addition to the increased performance, you reduce the number of I/O writes to only when you're saving the image file, which is configurable. For me, I save the image file every 5 minutes. Thus I only have 12 writes per hour. Not the several hundred thousand per hour I was experiencing.
If you have a 32 bit OS, using a small 50 - 300 MB RAM disk for the IE cache or Firefox profile would work nicely. Configure your browser to not save cache files or to clear them frequently. I use CCleaner to auto clear things every time I boot up.
I have been using this for several months with great results and have yet to encounter something exceeding the small temp/cache space RAM drive size.
|Re: Do NOT move your Chrome Internet Cache (or any other browser cache) off of your SSD.||4DGeorge||10/25/10 4:23 PM|
Now if I could just figure out how to move the very I/O write intensive search indexing and VIPRE anti-virus databases onto the RAM drive, too.
|Re: Do NOT move your Chrome Internet Cache (or any other browser cache) off of your SSD.||david.king||10/26/10 6:37 AM|
This is a neat post okashira, well said!
|Re: Do NOT move your Chrome Internet Cache (or any other browser cache) off of your SSD.||min2209||11/30/10 4:57 PM|
On the contrary, no. This is bad advice.
This totally ignores the concept of wear amplification. In the BEST CASE SCENARIO you will write continuous data to the drive, i.e. you write one 120GB data file, erase, then repeat - this will get you your 600TB written before failure.
If your SSD has a block size of 256KB, then it would have something like 480000 blocks for a 120GB drive. Assuming a P/E endurance of 5000, a program can destroy your SSD after 300MB of data written to it by writing one bit to each cell, and then erasing it.
Problem is, caches does pretty much something similar to this - write small files, then erase. I am up to 110 P/E cycles now with 160GB written to my 120GB SSD, in which case the OP's calculation method (which gives me 1.3 average cycles) is giving a life expectancy of 80 times what it actually is.
|Re: Do NOT move your Chrome Internet Cache (or any other browser cache) off of your SSD.||JakeHB||6/30/11 9:33 AM|
Most people are not concerned with wear. The problem is write speed. Many SSD netbooks have slow write speed which causes hanging while browsing the web. Firefox caching options are more flexible than Chrome. I've noticed on my Acer Aspire One that Chrome is blazing fast when I first install it, then it slows down and starts hanging and occasionally crashes. There doesn't seem to be a way to change the cache size in Chrome, nor disable it completely.