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msmth928

macrumors regular
Jun 3, 2009
154
0
I got it from dabs for £130.71. it was a "used stock" drive but im not too bothered about that. Also with 2.06% cash back with topcashback it worked out to be basically £1 per Gb

Came yesterday and took about 40 mins to get up and running, really pleased

Thanks - I haven't heard of topcashback before, will check them out. Do they charge you £5 a year like quidco does?
 

r17z

macrumors newbie
Feb 26, 2011
6
0
Thanks - I haven't heard of topcashback before, will check them out. Do they charge you £5 a year like quidco does?

umm to my knowledge there's no membership fee but its pretty slow in processing the cashback, I started using it properly about 2 months ago and the payouts are only just starting to happen
 

seanmorr

macrumors newbie
Nov 6, 2011
23
0
I went ahead and got a crucial m4 256gb drive and installed it in my late 2011 15"...working great, no problems and very fast. Have not enabled TRIM yet.
So far very happy with the m4
 

Erasmus

macrumors 68030
Jun 22, 2006
2,756
298
Australia
what exactly does the TRIM do?

My understanding is that the flash cells in a SSD have three states: clear, zero and one. Obviously, data is stored on a SSD with ones and zeros like a traditional HDD. However, changing a cell (i.e. writing) from clear to one or zero is much faster than going from one to zero, or vice versa.

Therefore, TRIM is simply an OS algorithm that uses a small amount of CPU time to look through the SSD for any ones or zeros that don't have any data pointers to them (i.e., trashed/deleted data) and resets the cell states of these sectors to clear. Therefore next time something needs to be written there, the sector has already been prepared for the fastest possible write speed.

TRIM would therefore be separate to wear-levelling algorithms which instead seek to prevent a small number of flash cells from being over used, eg. by writing new data to sectors that haven't been used in a while. I would assume that this would result in very fragmented data after a while, but that doesn't affect the performance of an SSD like it does with a HDD.

EDIT: Just read the Wiki page: http://en.wikipedia.org/wiki/TRIM
 
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Hellhammer

Moderator emeritus
Original poster
Dec 10, 2008
22,164
582
Finland
what exactly does the TRIM do?

From the first post:

TRIM is a command that allows the operating system to inform the SSD controller which files are no longer in use. In other words, when you delete something from the ssd, the operating system does not erase the actual data from the drive, the OS will just mark that space as free space and overwrite the data when needed.

However, the issue with mainstream SSDs with MLC NAND is that only blocks can be erased, individual pages cannot be. To make this simpler, think page as a file and block as a folder. So, if you want to delete one file (page) inside a folder (block), the whole whole folder needs to be erased and rewritten to get rid of that file. The issue raises when you don't have TRIM because the SSD controller still thinks that the file is in use. When the OS decides to overwrite that file, you first need to read the whole block to the cache (usually DRAM) and then you can rewrite the folder (block). The difference is that if you had an empty block, only the write action would have to be done. Now the SSD needs to read the while block first and then write. For the end-user, that appears as performance degradation. It looks like your write speeds have gone and they can easily degrade by 50%.

With TRIM, the OS can inform when a file has been deleted and the SSD controller can do this action in the background. You won't have useless files floating around, thus write speeds will remain great.

Windows 7 supports TRIM on all SSDs. As of Mac OS X Snow Leopard 10.6.6, TRIM is enabled on 2011 Macs with SSDs. OS X Lion is to add TRIM support for all Apple SSDs. As of DP4, third party SSDs are not supported. This may change in the future though. For third party SSDs, there is TRIM Enabler, but it is known to cause problems for some SSDs see the forum thread for more info).

AnandTech's article covers this through with a great example. If you are interested in this whole performance degradation issue, read that, it will open your eyes a lot. In my opinion, the performance degradation issue is overhyped. Most of today's SSDs have very effective garbage collection which helps if your OS does not support TRIM. A good SSD will experience little to no degradation, even without TRIM.

My understanding is that the flash cells in a SSD have three states: clear, zero and one. Obviously, data is stored on a SSD with ones and zeros like a traditional HDD. However, changing a cell (i.e. writing) from clear to one or zero is much faster than going from one to zero, or vice versa.

Depends on the NAND type. SLC has two voltage states (0 or 1) because only a single bit can be stored in one cell. MLC stores two bits per cell, hence there are four voltage levels (00, 01, 10, 11).

The problem is that you cannot erase individual cells, or even pages. Only blocks can be erased. Without TRIM, when you write to block that has old data in it (i.e. you have deleted some it and OS has marked it as free space, but it's still in the NAND), the whole block must first be read to the cache before erasing and reprogramming the block with new and old data.
 

MJL

macrumors 6502a
Jun 25, 2011
845
1
Ping Hellhammer

You mention the Intel 320 series SSD. I've been reading a lot up about the 8Mb fault which every man and his dog seem to take as a software error.

IMHO it is a hardware design fault and it has all to do with the power failure capacitors. I've got total faith in the Intel 320 provided that you do not recycle power in a hurry or that the power gets partially lost. In fact I have just ordered one to test this hypothesis.

You may wonder why I say this but this is based on reading a very large number of complaints and some personal experiences with other computer driven hardware whose faults disappeared after ensuring that something has been powered down long enough for a total discharge. (remember the old days where you had to wait for a computer to be powered down for a full minute before you were allowed to turn it back on?). With the large capacitor bank I am sure that not even a minute will be sufficient. Ensure to set in the power saving that the HDD is always enabled and does not spin down after a while.

Similarly if your machine goes to sleep or hibernation and you restart after a rather short timespan you can expect problems too.
 
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Mac Husky

macrumors regular
Mar 28, 2009
238
0
Bavaria, Germany
I want to go for the Crucial M4 256 or 128 upgrading my Mac Pro soon. Last alternative is the Samsung SSD 830. Using Adobe Photoshop (and sometimes Premiere Pro and Handbrake as well).

Maybe I missed it, reading this whole thread: Advantage of the Crucial over many other SSD seems to be, that it can be upgraded with firmware not using a PC but within the Mac. How about the Samsung concerning this point?!

I would like to avoid TRIM enabler as long as possible due to many bad things I heared about stocking systems. I hate Apple for that damned childish "Only-our´s SSD-TRIM" stuff. Of course I know, why the do it ;-)
 

Hellhammer

Moderator emeritus
Original poster
Dec 10, 2008
22,164
582
Finland
I want to go for the Crucial M4 256 or 128 upgrading my Mac Pro soon. Last alternative is the Samsung SSD 830. Using Adobe Photoshop (and sometimes Premiere Pro and Handbrake as well).

Maybe I missed it, reading this whole thread: Advantage of the Crucial over many other SSD seems to be, that it can be upgraded with firmware not using a PC but within the Mac. How about the Samsung concerning this point?!

I would like to avoid TRIM enabler as long as possible due to many bad things I heared about stocking systems. I hate Apple for that damned childish "Only-our´s SSD-TRIM" stuff. Of course I know, why the do it ;-)

Samsung does not have a Mac updater. However, you only need a PC to create the installer, so you don't need to load Windows to your Mac. Just having access to a Windows machine is enough.
 

MJL

macrumors 6502a
Jun 25, 2011
845
1
If you can find them then the Intel x25M-G2 is the most reliable SSD around. Either that one or a Crucial M4.

(PS Once it is working do not fiddle around with it (upgrading firmware) - I regret upgrading the EFI in my Mac mini 2011 and cannot undo it.)

Many are looking at the performance but it hardly makes a difference in normal desktop use - it is all about avoiding the seek delay which is normally < 0.1 mSec ffor a SSD and around 10-12 mSec for a mechanical HDD.


some interesting statistics here:
http://www.behardware.com/articles/843-7/components-returns-rates-5.html
 

ljx718

macrumors 6502
Dec 13, 2008
428
2
If you can find them then the Intel x25M-G2 is the most reliable SSD around. Either that one or a Crucial M4.

(PS Once it is working do not fiddle around with it (upgrading firmware) - I regret upgrading the EFI in my Mac mini 2011 and cannot undo it.)

Many are looking at the performance but it hardly makes a difference in normal desktop use - it is all about avoiding the seek delay which is normally < 0.1 mSec ffor a SSD and around 10-12 mSec for a mechanical HDD.


some interesting statistics here:
http://www.behardware.com/articles/843-7/components-returns-rates-5.html

you wouldnt put the samsung 830 up there in reliablity? im choosing between the crucial m4 and samsung 830. i know the 830 is a bit faster, but which would be the most reliable?
 

MJL

macrumors 6502a
Jun 25, 2011
845
1
you wouldnt put the samsung 830 up there in reliablity? im choosing between the crucial m4 and samsung 830. i know the 830 is a bit faster, but which would be the most reliable?

That's always the big question. I know initial Samsung SSD's had their issues but later they got it to work very well. That they are not represented in that list does not mean anything, they may not be available in that country (just like in ours where it is not available). There initially some issues with the crucial but I understand that since the firmware update those complaints have disappeared. Better the devil you know than the one you don't would be my suggestion. One thing to consider is how easy would it be to exchange?

My 40 Gb Intel series 320 came in today and I have put it into the second bay in my laptop and have set the power setup to switch it off 30 seconds after use. Lets see if I can break it in that way. (However it may well be that it is a combination of certain computers / settings which will break it so it proves nothing if it does not break. I am hoping it will break predictably so I can test the hypothesis.) Ideally this needs to be done with a large number of SSD and not one.
 

Mac Husky

macrumors regular
Mar 28, 2009
238
0
Bavaria, Germany
A few days ago Hellhammer wrote:
You could consider e.g. Samsung PM830 in that case. It has more aggressive GC, which is useful since OS X lacks TRIM support for 3rd party SSDs. Another option would be M4 with TRIM enabled.
I have seen a test yesterday, where Garbage Collection of the Crucial M4 AND the Samsung SSD 830 as well has been described as conservative. Intels 510 series is told to be noticeable more aggressiv.

But I don´t care. I bet GC works well in all of them as far as I will notice. The missing TRIM function in a Mac (without enabling) is the bigger problem. Thank you, Apple :mad:
 

MJL

macrumors 6502a
Jun 25, 2011
845
1
Another report:

http://darkstone.tweakblogs.net/blog/6956/ssd-betrouwbaarheidsonderzoek-de-resultaten.html

As far as the TRIM goes there is a simple solution and that is to replace the Apple SSD name with spaces according to the method of Grant Pannell and a script (trim_patch_sh - Github) from lloeki. It is simple and works fine.

In light of all the issues around I think it would for me still be a toss up between the Crucial M4 and the Intel series 320. One thing I learned as a HAM (amateur radio) operator was that with morse the "shape" of the on-off signal was important for longevity of transitor output and signal integrity. Unfortunately (and I am not privy to the exact details in the 320 series) capacitors used in power supplies can have a very wide tolerance (+100% / - 50% among the most common ones used) which can affect the shaping quite badly - I often had to work with tolerances below 10% to get a good/perfect shaping.

But from the earlier mentioned link in this posting and the previous posting it is clear that some of the other SSD vendors fare a lot worse than Intel.
One other item that many conveniently forget is that mechanical HDD have a failure rate which is also around the 1.5 - 2.5 % and that a lot of the 2.5" drives fail around the 18 months. Once HDD manufacture starts up again I do expect a far worse figure because a lot of the machinery is presently under water and who knows if the motor manufacturing will ever get back to normal (there is only one manufacturer who is about the sole supplier of the all HDD motors to the HDD manufacturers (or should I say "HDD assemblers"?)

The fault of a lot of the furore is that the SSD manufacturers have presented the SSD as ultra reliable which is not the case.
 

Mac Husky

macrumors regular
Mar 28, 2009
238
0
Bavaria, Germany
As far as the TRIM goes there is a simple solution and that is to replace the Apple SSD name with spaces according to the method of Grant Pannell and a script (trim_patch_sh - Github) from lloeki. It is simple and works fine.
I found a tutorial in a German forum some weeks ago. Seems to be a plagiarizm reading and comparing it with the tutorial of Grant Pannell :D

Yes, obviously the restriction by Apple concerning the TRIM function is due to a 9 signs long string. Apple´s SSDs are named "APPLE SSD". Upgrading a third party SSD, the SSD will of course have another name. The trick is to make the system recognize this new name. So TRIM will be available for any other SSD on the part of OSX. The tutorials show how to do that.

BUT: Updating OSX will overwrite these changes.

Unfortunately it seems to be impossible to rename any other SSD to "APPLE SSD"?!



Maybe Trim Enabler 2 will be a reliable way without the reported problems of the past?!
Should leave the beta phase soon.
 
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MJL

macrumors 6502a
Jun 25, 2011
845
1
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Weaselboy

Moderator
Staff member
Jan 23, 2005
34,136
15,597
California
And once the program is in memory then it does not matter a lot how fast the disk drive is except when you are ripping video's or doing some rendering.

I would partly agree with this. I agree once the app is loaded it does not make as much difference when using an SSD, but it does make some difference and it is noticeable. For example, when using Safari the web page data is cached and this occurs much faster/smoother with an SSD then a HDD. Same for iPhoto... even if iPhoto is already loaded it needs to load up the photo once you click on it and that is much faster with an SSD.

I have a 2010 iMac with HDD and a 2011 Macbook Pro with SSD, and in using both machines the SSD equipped Macbook Pro feels faster in normal usage even after all the apps are loaded even though the iMac has a much more powerful CPU/GPU.
 

Sasha-1

Contributor
Aug 11, 2001
467
182
I would partly agree with this. I agree once the app is loaded it does not make as much difference when using an SSD, but it does make some difference and it is noticeable. For example, when using Safari the web page data is cached and this occurs much faster/smoother with an SSD then a HDD. Same for iPhoto... even if iPhoto is already loaded it needs to load up the photo once you click on it and that is much faster with an SSD.

I have a 2010 iMac with HDD and a 2011 Macbook Pro with SSD, and in using both machines the SSD equipped Macbook Pro feels faster in normal usage even after all the apps are loaded even though the iMac has a much more powerful CPU/GPU.

It is indeed noticeable. I was considering returning my SSD after reading the horror stories. I even popped it out and put back the normal drive. After using my mac for all of ten minutes I couldn't stand it. I popped the SSD back in. Once you get used to the SSD being there, going back, at least to me, is impossible.

I'd say the SSD is the most significant upgrade you can make on your laptop these days. I was skeptical when I read others saying that. Microsoft Outlook in particular is so slow without an SSD. With a regular hard drive, the first launch of it after a boot is extremely slow. It must have been 6 or 7 bounces to start. If you quit it and then re-launch it, it opens in one bounce. With an SSD drive, first launch or second launch, it doesn't matter. You won't get to half a bounce and the app is already running.

With an SSD, everything pretty much feels like it's already loaded and you're merely switching to it. It's that fast. At least mine is. And once you get used to that, using a machine without an SSD feels like you are using a machine from 1995. You will right away find yourself wondering why it takes so long.

Boot time is that way too. It is dramatic to see the difference without an SSD. We have these nice Core i7 quad processor cores. Lots of RAM. But the hard drive is indeed holding it all back. The hard drive feels like it's a decade out of date.

What I'd like to see going forward are the loss of horror stories. These SSD drives need to become so reliable that even the worst bargain basement units from a used electronics store should be good for many years of solid use. The technology needs to become bullet proof. Because once you own one of these SSDs you'll find it very hard to go back. I want to put an SSD in my iMac now. I've been thinking of putting together external SSDs for backup rather than traditional hard drives in FireWire cases.

Speaking of external hard drives, we need SSD in Thunderbold 2.5" external cases for back up. No more of this slow FireWire and USB. I need to a minimum of 250 Megabytes a sec now.
 
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