which SSD should i get?

[Per Hansson]

Re: which SSD should i get?

There is no such correlation.
It all depends on controller manufacturer, NAND manufacturer / type & firmware

[eccerr0r]

Re: which SSD should i get?

goontron, have fun with your new ssd.

I wish I had a Microcenter near me, BB sux, and MC is sometimes fairly competitive with Internet prices sometimes despite having to maintain a B&M presence...

[dood]

Re: which SSD should i get?

Yours has been kept running more continuously and has seen ~14 times less power ons.

My computer stays on most of the time during the winter, running Folding@Home. During the summer, it actually stays off most of the time. So yeah, not too many power on/off cycles.

[shovenose]

Re: which SSD should i get?

My computer stays on most of the time during the winter, running Folding@Home. During the summer, it actually stays off most of the time. So yeah, not too many power on/off cycles.

Please remember to turn of scheduled defrag on SSD. It will kill it, fast.

[goontron]

Re: which SSD should i get?

Please remember to turn of scheduled defrag on SSD. It will kill it, fast.

what the hell is "defraging" anyway? i know its a windows term but......... is it a decrepancy in NTFS?
a sun Solaris machine was my first computer so......

[eccerr0r]

Re: which SSD should i get?

Actually file fragmentation will happen to all filesystems - you can always get a degenerate file allocation that will cause fragmentation, just that it is possible to resist it. It's just that doing defragmentation on multiuser systems is extremely costly (typically a shutdown is needed or complicated cache coherency).

Even funnier - the systems made to resist fragmentation involve using extents - but look at this new problem: extents tends to be on different portions of the disk and seeking between them is now an issue since seeking between them now takes more time!

Of course with SSDs this problem goes away. At least until you run out of free erase blocks. The hardware still can cleverly hide this away though.

[TELVM]

Re: which SSD should i get?

Why defragging HDDs is a good idea

Why defragging SSDs is a very bad idea

[goontron]

Re: which SSD should i get?

Actually file fragmentation will happen to all filesystems - you can always get a degenerate file allocation that will cause fragmentation, just that it is possible to resist it. It's just that doing defragmentation on multiuser systems is extremely costly (typically a shutdown is needed or complicated cache coherency).

Even funnier - the systems made to resist fragmentation involve using extents - but look at this new problem: extents tends to be on different portions of the disk and seeking between them is now an issue since seeking between them now takes more time!

Of course with SSDs this problem goes away. At least until you run out of free erase blocks. The hardware still can cleverly hide this away though.

well with journalling file systems like ext4 the physical mapping of the file system is basically a hierarchical structure of contiguous blocks containing a journal logging file operations so files and their attributes and metadata are only logical entities reconstructed from the journal, so that means that there is not much fragmentation at all and i think ZFS works about the same way so you dont really need to defrag them at all.

[dood]

Re: which SSD should i get?

Please remember to turn of scheduled defrag on SSD. It will kill it, fast.

Well aware of the SSD tips and tricks. Probably have about 2 dozen of them deployed at this point.

[eccerr0r]

Re: which SSD should i get?

well with journalling file systems like ext4 the physical mapping of the file system is basically a hierarchical structure of contiguous blocks containing a journal logging file operations so files and their attributes and metadata are only logical entities reconstructed from the journal, so that means that there is not much fragmentation at all and i think ZFS works about the same way so you dont really need to defrag them at all.

Journaling has nothing to do with fragmentation, journaling is only good to minimize the chance of half baked writes.
And as I said, extents is what is used in ext4 and other filesystems to reduce chance of fragmentation. It only reduces chances, it cannot prevent.

How about a degenerate case?

1. Fill your disk with small files until it is full, I mean millions of these files. Even better, make hundreds of processes that create these random small files.
2. Randomly delete 1/4 of these files to free up 1/4th of the disk space.
3. Create a big file to fill the freshly released space.

This file you just created will be fragmented and there's nothing can be done to prevent this file from being fragmented other than hot-defragmentation that some filesystems offer - before the file gets written. But hot defragmentation costs performance and you will lose real time performance if this is done.

Again this is a very contrived case, but it demonstrates why there are no fragment free file systems. A way to prevent this from happening is to over provision your hard drive space - Don't fill your hard drive partition to the gills. Keep at least 1/4 or so free so there will always be the chance of a large free extent.

And BTW, unless the SSD over provisions or intelligently garbage collects in the background with TRIM, this kind of operation will make writing that new file quite slow.

Linux has been boasting fragmentation resistant filesystems for years, even for ext2. However if you've tried using sparse file bittorrent on ext2 you know this is not true - the files that are created are very fragmented. Yes, you can preallocate the file to prevent this from happening and not use sparse files, but that's the user trying hard to prevent fragmentation, not the filesystem.

[migel_prado]

Re: which SSD should i get?

Intel's SSD 525/530 must be reasonably good choice, Most reliable SSD is Intel Sf based SSD which is one of the best in the market as of today. Why pay more for something that will perform the same doing the same task?? Also you will find Sf controller series which supports both SATA III and PCI can read up to 1800 MB/s and are pretty good. Check this - http://www.tweaktown.com/news/33957/...b-s/index.html

[tmiha71]

Re: which SSD should i get?

Hey T...,
what about SWAP file on SSD ?
what about - FA Table, NTFS table, and other FS tables which are constantly modified...

In link you sent, there's error...

The key benefit to SSDs is that they have virtually no seek time.

Should be...

The key benefit to SSDs is that they have no seek time.

And fragmentation is no problem for SSD, because it is (organized as) memory, and it's accessed like memory...

[TELVM]

Re: which SSD should i get?

... what about SWAP file on SSD ?

If there has to be a pagefile located on physical drive, much better to place it in SSDs, which sport miles better 4K performance than spinners (although the extra writes will shorten the SSD's life, if that worries us).

Better still to get plenty of RAM and live with no pagefile at all, or just a vestigial one located in ramdisk (to quiet down those dumb programs that start bitching when they can't find a pagefile, even when there are 32GB of memory).

... what about - FA Table, NTFS table, and other FS tables which are constantly modified...

That goes with the territory if OS is installed on SSD.

Browsers also do a lot of writing all the time. I always move Firefox/Pale Moon whole profile into ramdisk, this spares the SSD all that writing and also speeds things up.

[goontron]

Re: which SSD should i get?

If there has to be a pagefile located on physical drive, much better to place it in SSDs, which sport miles better 4K performance than spinners (although the extra writes will shorten the SSD's life, if that worries us).

Better still to get plenty of RAM and live with no pagefile at all, or just a vestigial one located in ramdisk (to quiet down those dumb programs that start bitching when they can't find a pagefile, even when there are 32GB of memory).



That goes with the territory if OS is installed on SSD.

Browsers also do a lot of writing all the time. I always move Firefox/Pale Moon whole profile into ramdisk, this spares the SSD all that writing and also speeds things up.

well that doesnt help with the legacy machines <2gb ram

[ratdude747]

Re: which SSD should i get?

If there has to be a pagefile located on physical drive, much better to place it in SSDs, which sport miles better 4K performance than spinners (although the extra writes will shorten the SSD's life, if that worries us).

Better still to get plenty of RAM and live with no pagefile at all, or just a vestigial one located in ramdisk (to quiet down those dumb programs that start bitching when they can't find a pagefile, even when there are 32GB of memory).



That goes with the territory if OS is installed on SSD.

Browsers also do a lot of writing all the time. I always move Firefox/Pale Moon whole profile into ramdisk, this spares the SSD all that writing and also speeds things up.

well that doesnt help with the legacy machines <2gb ram

Not to be a prick, but why invest in an SSD for a machine old enough not to have that much RAM? Such a system probably doesn't have SATA III either, so the interface will be a bottleneck. Yeah, it will be faster... but you won't be getting your money's worth, at least in my opinion.

On a different not, my SSD doesn't have any swap partitions or page files... my 8GB of ram is plenty, and if I need more I'll just buy more.

[goontron]

Re: which SSD should i get?

Not to be a prick, but why invest in an SSD for a machine old enough not to have that much RAM? Such a system probably doesn't have SATA III either, so the interface will be a bottleneck. Yeah, it will be faster... but you won't be getting your money's worth, at least in my opinion.

yer i know i was talking about legacy machines which my laptop isn't
my laptop has 16gb ram, 4 core AMD, a BD-RW drive and currently an 80gb spinner from Seagate ( the 500gb shit the bed. damn it Toshiba! ) and i now have $130 to spend on one so time to go through my options. again.......
and it narrowed down rather fast.

SanDisk Extreme Il Marvell Controller http://www.microcenter.com/product/4...ell_Controller

or

Crucial M500 Series Marvell Controller http://www.microcenter.com/product/4...187_Controller

which one should i get?

[TELVM]

Re: which SSD should i get?

well that doesnt help with the legacy machines <2gb ram

One of the dinosaurs in my small museum of relics is a Pentium III 1400-S slocketed on an ancient 440BX mobo with just 768MB of RAM . Pale Moon's 3.6.32 profile is located at an on-the-fly variable-size ramdisk of up to 256MB. You can still browse today's bloated internet with reasonable decency on this relic.

Not to be a prick, but why invest in an SSD for a machine old enough not to have that much RAM? Such a system probably doesn't have SATA III either, so the interface will be a bottleneck. Yeah, it will be faster... but you won't be getting your money's worth, at least in my opinion ...

You're completely right, not worth the trouble for the vast majority of people.

That said, if you happen to belong to the crazy beyond hope tinkering minority , you can plug the SSD on a PCI SATA controller and enjoy the 'warping speeds' .

[goontron]

Re: which SSD should i get?

You're completely right, not worth the trouble for the vast majority of people.

yes but the computer i am buying this for is a rather good laptop!

my laptop has 16gb ram, 4 core AMD, a BD-RW drive and currently an 80gb spinner from Seagate ( the 500gb shit the bed. damn it Toshiba! )

That said, if you happen to belong to the crazy beyond hope tinkering minority

im part of that minority, especially if you consider hand winding transformers nuts....

anyway im thinking of the SanDisk, any objections?

[Per Hansson]

Re: which SSD should i get?

im part of that minority, especially if you consider hand winding transformers nuts....

anyway im thinking of the SanDisk, any objections?

The Sanddisk is great, same controller as the M500 you listed aswell but better NAND so it is much faster, which is reflected in the drives price too of course

As for the crazy bit, I have an IBM Thinkpad T40 with a Plextor mSATA 120GB SSD PX-128M5M (It also has the same controller as the above two drives)
It's connected to the internal IDE port via a 2.5" to mSATA adapter I bought on eBay, works amazingly well!

[TELVM]

Re: which SSD should i get?

... As for the crazy bit, I have an IBM Thinkpad T40 with a Plextor mSATA 120GB SSD PX-128M5M (It also has the same controller as the above two drives)
It's connected to the internal IDE port via a 2.5" to mSATA adapter I bought on eBay, works amazingly well!

And yet there is method in our madness!

Notice how even the Paleozoic PIII/SSD concoction just creams a fast modern spinner @ 4K :

. . .