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MacGizmo

macrumors 68040
Apr 27, 2003
3,198
2,501
Arizona
Could you elaborate on why it has twice the lifespan? Are you saying a 2tb ssd will last longer than a 1tb? how?
I'm not sure that statement is accurate when applied as a blanket over all SSDs—I'm not an expert in this field—but SSD's have a finite amount of writes before they stop working.

In theory, a 2TB SSD would have twice as many writes available than a 1TB SSD–but that could be fudged by manufacturers (they could use a lower quality chipset that only allows X amount of writes no matter what capacity the SSD is). And even if it isn't, the "lifespan" is completely dependent on how often you write to the drive... lots of little writes eats into that finite number faster than one large write (again, in theory).

As far as the speed of the drive, that has nothing to do with the storage capacity. I've seen plenty of 500GB SSDs that are MUCH faster than 1TB SSDs. By coincidence though, as drives get larger they also get faster, so it's difficult to prove that out.

So in short, what Mac Hammer Fan said is absolutely true... except when it's not. 🤪
 

Mac Hammer Fan

macrumors 65816
Jul 13, 2004
1,326
497
Could you elaborate on why it has twice the lifespan? Are you saying a 2tb ssd will last longer than a 1tb? how?


TBW Figures

250 GB SSD = 150 TBW
500 GB SSD = 300 TBW
1TB SSD = 600 TBW
2TB SSD = 1200 TBW
 
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Fishrrman

macrumors Penryn
Feb 20, 2009
29,175
13,225
Re the above posts about "swap".

If you're worried about VM disk swapping, buy sufficient RAM.
Then TURN OFF VM disk swapping using the terminal.

I've been running my Macs this way FOR YEARS now, with no ill effects.
 

handheldgames

macrumors 68000
Apr 4, 2009
1,943
1,170
Pacific NW, USA
Re the above posts about "swap".

If you're worried about VM disk swapping, buy sufficient RAM.
Then TURN OFF VM disk swapping using the terminal.

I've been running my Macs this way FOR YEARS now, with no ill effects.
I couldn't agree more about disabling SWAP. I've run that way for years. Now, with a portion of my pipeline running, I'm already at 32GB ram usage. Nothing like a swap free machine, allowing it to run at full speed unencumbered.
1674866687837.png
 

NJRonbo

macrumors 68040
Jan 10, 2007
3,231
1,222
Very interesting read here.

What is the terminal command to disable swap?

In doing so, am I essentially looking at longer SSD life out of my machine? Will I see any performance boosts?

I always buy 64GB of ram. My M1 Studio and 2021 16" MBP both have it. Very interested in what turning off swap will do.
 

Fishrrman

macrumors Penryn
Feb 20, 2009
29,175
13,225
NJRonbo asks:
"What is the terminal command to disable swap?"

To DISABLE virtual memory:

sudo launchctl unload -wF /System/Library/LaunchDaemons/com.apple.dynamic_pager.plist
(reboot necessary afterwards)

To REMOVE swap files:
sudo rm /private/var/vm/swapfile*

To check if VM is being used:
sysctl vm.swapusage

If VM is off, report should be:
vm.swapusage: total = 0.00M used = 0.00M free = 0.00M

Note:
All I've ever done is to DISABLE VM disk swapping.
I have NEVER turned it back on again, not sure if this is the right command, but here it is:

To enable swap, you need to boot in Single User Mode (Hold [CMD + S] at booting time) and run this command:
sudo launchctl load /System/Library/LaunchDaemons/com.apple.dynamic_pager.plist

Fishrrman's note:
These are from my archives.
Not sure if the "remove swap file" still works on latest OS's.
But the other commands do.
 

reboot81

macrumors newbie
Dec 2, 2010
16
0
Sweden
Having only used Intel Macs, current iMac 40GB, I'd say 32 would be fine.
However, knowing my system is heavily swapping I looked up my TBW on my interal 500.
Code:
Available Spare:                    100%
Available Spare Threshold:          10%
Percentage Used:                    44%
Data Units Read:                    1 079 138 319 [552 TB]
Data Units Written:                 723 958 241 [370 TB]

Yikes... time to order a Studio. With 64 and disabling swap.
 
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