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viizi

macrumors regular
Original poster
Dec 2, 2010
224
68
Lately I have been using Chrome and Safari for youtube (Html5).

I have my default cache folder for everything located on an external USB3 drive so my Fusion(SSD) stays at lower writes for a prolonged life.

Using iStat Menus I have been monitoring which drive is receiving the writes and which isn't while viewing HTML5 youtube videos.

Chrome has been writing to the external USB3 drive while Safari is still writing to the SSD. Both cache folders are located on the external so my question is. Where does Safari store it's HTML5 video cache if not in the default cache folder where it stores the rest of the cache from browsing? I have even checked the safari cache folder size before and after watching a youtube video in safari and it the file size has not changed. It is writing to an alternate location outside of the system's cache folder.
 
How much data is written to your SSD on a daily basis, if the caches would be located there?
Would it be 50 GB per day? If so, that is no problem for an SSD, as even with 50 GB per day writes to it for 365 days and 5 years it only accumulates to 90 TB, which is within the limits of writes of most SSDs anyway.

I have one SSD in my MBP and one SSD in my Hack and I do not divert the cache writing and READING to an HDD, as that would mean the loss of those fast random access times SSDs are there for.

As for your actual question, I cannot answer that. Sorry.
 
How much data is written to your SSD on a daily basis, if the caches would be located there?
Would it be 50 GB per day? If so, that is no problem for an SSD, as even with 50 GB per day writes to it for 365 days and 5 years it only accumulates to 90 TB, which is within the limits of writes of most SSDs anyway.

I have one SSD in my MBP and one SSD in my Hack and I do not divert the cache writing and READING to an HDD, as that would mean the loss of those fast random access times SSDs are there for.

As for your actual question, I cannot answer that. Sorry.

I don't mean to go against your theory but the app 'DriveDX' tells me my SSD health is down to 90% in less than a year while using my external cache method. I bet it would be down to about 50% health if I hadn't.

The writes without my cache method would be around 30GB-40GB a day.

Apple SSD SM128E (Samsung based) late 2012 iMac
 
I don't mean to go against your theory but the app 'DriveDX' tells me my SSD health is down to 90% in less than a year while using my external cache method. I bet it would be down to about 50% health if I hadn't.

The writes without my cache method would be around 30GB-40GB a day.

Apple SSD SM128E (Samsung based) late 2012 iMac

I just tested that application with my one year old Samsung 840 SSD and it has been running for 5.195 hours since I bought it and its "SSD Lifetime Left Indicator" is at 97%.
"241 Total LBAs Written" is at "17.311.516.844 (8.1 TB)" and the "Status" at "99%".

Those numbers accumulate to roughly 1,6 GB per hour written to it, which is roughly 38 GB per 24 hours.

Hmm, I do not know those iMac SSDs that well to know how soon they get lost, but with my SSD there is probably still 173.166.67 hours left on it before failing, which is another 19 years with my current usage pattern.

Sorry I cannot help you with the HTML5 video cache location, as I thought it would all go into the same cache in the Library folder.

https://forums.macrumors.com/threads/998363/
 
Lately I have been using Chrome and Safari for youtube (Html5).

I have my default cache folder for everything located on an external USB3 drive so my Fusion(SSD) stays at lower writes for a prolonged life.

Using iStat Menus I have been monitoring which drive is receiving the writes and which isn't while viewing HTML5 youtube videos.

Chrome has been writing to the external USB3 drive while Safari is still writing to the SSD. Both cache folders are located on the external so my question is. Where does Safari store it's HTML5 video cache if not in the default cache folder where it stores the rest of the cache from browsing? I have even checked the safari cache folder size before and after watching a youtube video in safari and it the file size has not changed. It is writing to an alternate location outside of the system's cache folder.

I just did some testing with YT vids and they seem to get cached in this user folder. As I watch one video after another more files get added to this folder and the size grows.

Code:
~/Library/Caches/com.apple.Safari/fsCachedData

That said, you really don't need to worry about this. If you have an Apple OEM flash storage device, those use MLC NAND chips rated at around 3,000 write cycles per cell. Take a look at this article and also this test. That SSD will likely last longer than your computer even at fairly high write cycles.

I use DriveDX just because I was curious about how SMART worked and all. I recall reading something in the devs. tech support that the way the lifespan estimate works tends to make the first 5-10% go pretty quickly then the rate slows. I noticed this with my 2013 MBA. I went from 100% down to 95% in the first few months then just kind of sat there. I think it had 94% when I sold it last week. I tried to find the link where I read that, but can't seem to locate it.
 
I just did some testing with YT vids and they seem to get cached in this user folder. As I watch one video after another more files get added to this folder and the size grows.

Code:
~/Library/Caches/com.apple.Safari/fsCachedData

That said, you really don't need to worry about this. If you have an Apple OEM flash storage device, those use MLC NAND chips rated at around 3,000 write cycles per cell. Take a look at this article and also this test. That SSD will likely last longer than your computer even at fairly high write cycles.

I use DriveDX just because I was curious about how SMART worked and all. I recall reading something in the devs. tech support that the way the lifespan estimate works tends to make the first 5-10% go pretty quickly then the rate slows. I noticed this with my 2013 MBA. I went from 100% down to 95% in the first few months then just kind of sat there. I think it had 94% when I sold it last week. I tried to find the link where I read that, but can't seem to locate it.

Yep youtube writes to that location when using flash to view the videos. When I switch to HTML5 it changes to somewhere else though
 
Yep youtube writes to that location when using flash to view the videos. When I switch to HTML5 it changes to somewhere else though

Nope. I do not even have Flash installed and watch using the Youtube5 extension that forces HTML5 and during my test the cache was going to that folder.
 
An update:

89% today in DriveDX. Ever since installing yosemite I have left the cache location default on the fusion drive instead of my external for performance sake. I am not sure if this had much of an effect to tick it from 90% down to 89% but I will monitor it over the next few weeks to see if it ticks again. It went down 1% in 2 months so that is pretty good so that is like 16 and a half years before 0% at that rate :D I just hope the cache location on the fusion drive doesn't lead to a percent tick per week. I'll update in a weeks time.
 
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