428678 Views Previous 1 2 3 4 … Next 101 Replies Latest reply: Aug 16, 2014 2:19 PM by Brendan1233 Go to original post
Well, here's the fruits of my researches:
SSDs work by using flash memory, which is actually very slow, but there is +a lot of it+ and it runs in parallel, so the overall performance is very high. This is important - any data is distributed across the drive, not in clumps like on a HDD.
Users typically notice that an SSD drive runs at the manufacturer's stated peak I/O performance at first, but soon after that it begins to drop. That's because, unlike a hard disk drive, any write operation to an SSD requires not one step, but two: an erase followed by the write.
Also, when an SSD is new, the NAND flash memory inside it has been pre-erased; Users start with a clean slate, so to speak. But, as data is written to the drive, data management algorithms in the controller begin to move that data around the flash memory in an operation known as wear-leveling. Even though wear-leveling is meant to prolong the life of the drive, it can eventually lead to performance issues.
That's still only a partial picture. More info here http://www.anandtech.com/show/2738/8
It's quite a drastic reduction, but if you're using something like the OCZ Vertex (Intel is better but pricier) SSDs are already something like 15x the speed of an Apple hard drive, so even after a performance drop it'll still be more than 10x.
Of much more concern here are reports about Apple's own SSDs that appear to be made by Samsung. "On no, it's an OCZ." you say. Uh oh. From what I've read OCZ's Apex and Summit (the one Apple uses) use rebranded Samsung drives.
+"My new SSD died"+ http://blogs.computerworld.com/mynew_ssd_died_dare_i_tryanother It was an OCZ Apex.
+"What's Wrong with Samsung?"+ http://www.anandtech.com/show/2829/19 Those figures look terrible!
There's a lot of rubbish on the net about this from folk who should know the limitations of their own knowledge better. For instance there's a persistent myth about de-fragging, indicating a complete lack of understand of how an SSD works. De-fragging (I'm pretty sure) might actually +slow it down+ and reduces the drive's lifespan!
I hope someone from Apple can chime in here and reassure folk...
Apple now uses Toshiba SSDs (at least 256GB/512GB) and for a wonder don't charge an arm and a leg when compared to other SSDs. I would recommend 8GB RAM though, that really helps SSDs perform much better cos' they don't have to store temp data on the hard disk anymore given 8GB RAM.
OWC SSDs are mighty expensive. I would go with Apple's SSDs (128GB or 256GB) cos' I am sure Apple is going to implement trim support soon and Apple's chosen SSDs may work better. All this only if Apple plays fair and decides not to sell incremental upgrades in the next iteration like they have been doing for quite some time.
3Gbps bottleneck is another to keep in mind. Don't expect speeds reviewed to hit your MacBook just yet.
I have been buying a MacBook every year btw. I sell it off bundled with my old iPhone for a decent price. This year I have figured out a super formula to save me more $$$ than before. (Student Discount + Tax Free state + iPod Touch + Printer + Affiliate Cashback/Discover Cashback)!
Nope. Here's Wiki:
+"TRIM has been integrated in Linux 2.6.33. In FreeBSD, TRIM functionality is available since version 9.0. In Microsoft Windows, TRIM has been implemented in Windows 7 and Windows Server 2008 R2, and was released with the final versions of those operating systems in October 2009. Older solid-state drives will need firmware updates, otherwise the new command will be ignored. Mac OS X does not support TRIM.+
+Where TRIM is not automatically supported by the operating system, there are utilities which can send TRIM commands manually. Usually they list all free blocks as specified by the operating system and then pass this list as a series of TRIM commands to the drive. These utilities are available from various manufacturers (Intel, G.Skill) or as general utilities (hdparm since v9.17)"+
Those are likely to be PC utils.
My guess is you may see it in the next OS upgrade. Or the one after that...
Or maybe there's something like that already there operating in the background..? There's an infuriating lack of info about this.
Affiliate cashback is from BigCrumbs (1.8%). Here is the chart for different configurations : http://bit.ly/MacBookProPriceChart (I liked those numbers and calculations).
I bought 2 80GB Intel X25 M 2nd gen SSDs. Will do a RAID 0 in a MBP and let you know guys!
I use a OCZ Vertex 2 and it seems fine. I believe it has automatic garbage collection, so clears unused cells automatically without TRIM support from the OS. I have run quite a few benchmark tests on it and get 250Mb/s Read and Write.
And due to the large amount of memory I have, I hope my Mac wont be memory swapping on the drive much, and therefore prolong its life.
If you want an update about TRIM Support I found this at:
"TRIM Support On the Way?
Several readers wrote me once they received their new 13-inch MacBook Pros and told me that System Profiler lists TRIM support as an option for SSDs on these systems. I confirmed:
This appears to be limited to the new 13-inch MacBook Pro. I tried my 2nd gen unibody 15-inch as well as the new 15-inch i5/i7 model and neither of them have TRIM listed as an option with an SSD installed. It appears that the driver for the GeForce 320M chipset in the new 13-inch MBP supports TRIM at some level.
The OS still incorrectly identifies SSDs with TRIM support as not supporting the instruction, but I get the feeling we're close to having TRIM support in OS X. At which point we'll be even closer to Apple shipping some halfway decent SSDs in their systems. It's taken this long but we're getting there."
Also something else I didn't see mentioned is that Trim won't work with RAID even in windows. If you can wait to buy one you should definitely hold off until 2011 as the SSD market will be changing for the better:
Intel's 3rd Generation X25-M SSD- (Anandtech)
"The new drive uses 25nm IMFT Flash, which means we should get roughly twice the capacity at the same price. While Intel is sampling 25nm MLC NAND today it's unclear whether or not we'll see drives available this year. I've heard that there's still a lot of tuning that needs to be done on the 25nm process before we get to production quality NAND. The third generation drives will be available somewhere in the Q4 2010 - Q1 2011 timeframe in capacities ranging from 40GB (X25-V) all the way up to 600GB."
Since price, storage capacity and the uncertainty of TRIM support or "wear-leveling" are the only things holding customers back, if intel can really deliver a high performance SSD with up to 600GB at virtually the same price as their old X25-M G2 its introduction into such a competitive market will (hopefully) drive prices down. Both OS and SSD need to support TRIM so hopefully apple will introduce this soon. SSDs are still going to be luxury items though.
If you want to know more about performance degradation: http://www.anandtech.com/show/2738/8
It's an old article and a long read. It isn't the first page of the entire article "The SSD Anthology" but the next few pages have info on TRIM etc.
If you're wondering about SSD that don't support TRIM, here's some info:
"No TRIM, but Garbage Collection
The IBIS drive features a four-controller internal RAID, and there’s currently no way to pass TRIM along to drives in a RAID array, which means its very important to have a resilient controller. OCZ stuck with SandForce and the SF-1200, the most resilient controller on the market today. To make things better however the drive supports idle time garbage collection. With an active NTFS partition on the drive, no IO activity and sufficient free space, the controllers will begin cleaning up the NAND. The effect is profound, below we have a clean drive:
Now, after we've filled the drive and tortured it with random writes:
Note that peak low queue-depth read speed dropped from ~233MB/s down to 120MB/s. Now here’s performance after the drive has been left idle for half an hour:
Remember this is very low queue depth testing so the peak values aren't very high, but it's enough to show the idle garbage collection working."
Look out for SandForce controllers, they're definitely the best. Wear levelling is also sometimes called "garbage collection" and is quite effective. This came from the article "OZX's Fastest SSD, The IBIS and HSCL interface reviewed":
second generation Sandforce SSDs, the SF-2000 series will also be out 2011
OCZ vertex 2:
if you're still interested in Vertex you should look at what Anandtech has to say about them.
Hope this helped you, and anyone else wondering about SSDs
You can probably tell I've been wanting one for ages
btw, I was able to install my entire system from external backup drive using Time Machine. You just boot from startup disk (on your new SSD) don't start any installations, just click up the top and look through utilities until you find timemachine, select, and it does it all for you. You only need one backup of your system and time machine will work. You don't need to update or install anything. I had some finder windows open while I was shutting down the computer and, after a wiped the drive completely and installed my system from back up and rebooted, they opened again on startup! Just seems easier than having to use SuperDuper to me. Even if you don't use time machine for this you should probably consider using it to make regular backups on your new drive.
Goodluck finding a new drive, if you haven't already got one.
This is the most recent mention I could find on apple SSD on Anandtech when he was talking about Mac Pro:
"If you order an Apple SSD, either as an upgrade kit or with your Westmere Mac Pro you'll get a 2.5" adapter for the 3.5" drive sled. While I would've preferred something in-box for all users (since I still recommend going your own route for SSDs vs. buying them from Apple), this is at least a step in the right direction"
and later in the same article:
"I would still like to see Apple offer SSDs as standard, particularly in this price class. On top of that I'd like to see OS X get TRIM support and some faster SSDs as options in the Apple store. SandForce anyone?"
To answer your question, I don't think there would be a difference. A larger drive would take longer to fill up obviously, but other than that they're probably all the same.
What you need to know is whether they have idle garbage collection etc. (explained below) and also what controller they have.
There is also an article on an apple SSD that I will put a link to at the bottom.
I think its more important that you get a better understanding of SSDs so here's some info. Oh, and in my last post I was confused- wear levelling and idle garbage collection are different.
From SSD relapse: Understanding and choosing the best SSD:
http://www.anandtech.com/show/2829/1"A Wear Leveling Refresher: How Long Will My SSD Last?
As if everything I’ve talked about thus far wasn’t enough to deal with, there’s one more major issue that directly impacts the performance of these drives: wear leveling.
Each MLC NAND cell can be erased ~10,000 times before it stops reliably holding charge. You can switch to SLC flash and up that figure to 100,000, but your cost just went up 2x. For these drives to succeed in the consumer space and do it quickly, it must be using MLC flash.
Ten thousand erase/write cycles isn’t much, yet SSD makers are guaranteeing their drives for anywhere from 1 - 10 years. On top of that, SSD makers across the board are calling their drives more reliable than conventional hard drives.
The only way any of this is possible is by some clever algorithms and banking on the fact that desktop users don’t do a whole lot of writing to their drives.
Think about your primary hard drive. How often do you fill it to capacity, erase and start over again? Intel estimates that even if you wrote 20GB of data to your drive per day, its X25-M would be able to last you at least 5 years. Realistically, that’s a value far higher than you’ll use consistently."
Spare room on SSD
"Intel's 80GB X25-M has 80GB of NAND flash on it. That's 85,899,345,920 bytes or 80 x 1024^3 bytes (1024 bytes in a kilobyte x 1024 kilobytes in a megabyte x 1024 megabytes in a gigabyte x 80 gigabytes)."
"How much space is there really on the drive? 80GB. How much space does Windows let you use? 74.5GB. What happens to the remaining 5.5GB? It's used by the drive's controller as spare area.
Intel’s controller is dynamic, it uses the entire drive as spare area until you’ve written every LBA once. Then it relies on the remaining 7.5% of non-user-space as its scratch pad. That’s why its new, out of box, performance is so good.
Other controllers may not be quite as dynamic, but they may also take a smaller performance hit when fully used. Why would Intel work so hard to make its out of box performance so high, even when it’ll be short lived? Because of TRIM."
What TRIM does is help give well architected controllers like that in the X25-M more spare area. Space you’re not using on the drive, space that has been TRIMed, can now be used in the pool of replacement blocks. And as IBM’s study shows, that can go a long way to improving performance depending on your workload."
Keep in mind that this article is old and a lot of these now support TRIM-
"Tying it All Together: SSD Performance Degradation
More spare area is better for random workloads, but desktop workloads aren’t random enough to justify setting aside more spare area to improve performance; most reviews don’t test in a used state, and more users would simply flock to lower price-per-GB drives with less spare area.
Drives that drop the most in performance from new to used state have the most to gain from the TRIM instruction. Depending on how you use your drive of course:
Depending on the scenario, all three controllers have a lot to gain from TRIM. Random write performance drops significantly for almost every single drive. The worst is the Samsung RBB controller, which lost over 70% of its performance between new and used states; Samsung needs TRIM.
Intel made some significant improvements going from the G1 to G2 drives, the new drive loses no performance in our random write test. This is thanks to firmware tweaks and having twice as much DRAM to track data in; the more data the Intel drive can keep track of, the better it is at organization, management and garbage collection. From a pure performance standpoint, the G2 might actually be better for server workloads than the X25-E. In terms of lifespan however, the X25-E has the G2 beat.
Only the Indilinx drives lose an appreciable amount of performance in the sequential write test, but they are the only drives to not lose any performance in the more real-world PCMark Vantage HDD suite. Although not displayed here, the overall PCMark Vantage score takes an even smaller hit on Indilinx drives. This could mean that in the real world, Indilinx drives stand to gain the least from TRIM support. This is possibly due to Indilinx using a largely static LBA mapping scheme; the only spare area is then the 6.25% outside of user space regardless of how used the drive is.
Both Samsung and Intel have a lot to gain from TRIM. Samsung’s performances goes from utterly unacceptable to reasonable (but not price justified) with TRIM. Intel’s performance goes from class-leading to more, er, class-leading."
Some SSDs only have idle garbage collection and I think sandforce controllers are the best when it comes to this-
"Impact of Idle Garbage Collection
The other option that Indilinx provides its users to improve used performance is something called idle or background garbage collection. The idea is that without any effort on your or the OS’ part your drive, while idle, will defragment itself.
It either works by looking at the data on the drive and organizing it into a less fragmented state, or by looking at the file system on the drive and attempting to TRIM based on what it finds. Both Indilinx and Samsung have attempted to implement this sort of idle garbage collection and it appears they do it in different ways. While the end result is the same, how they get there determines the usefulness of this feature.
In the first scenario, this is not simply TRIMing the contents of the drive, the drive doesn’t know what to TRIM; it must still keep track of all data. Instead, the drive is re-organizing its data to maximize performance.
The second scenario requires a compatible file system (allegedly NTFS for the Samsung drives) and then the data is actually TRIMed as it would be with the TRIM instruction.
Presumably this isn’t without some impact to battery life in a notebook. Furthermore, it’s impossible to tell what impact this has on the lifespan of the drive. If a drive is simply reorganizing data on the fly into a better (higher performing) state, that’s a lot of reads and writes when you’re doing nothing at all. And unfortunately, there’s no way to switch it off.
While Indilinx is following in Samsung's footsteps with enabling idle garbage collection, I believe it's a mistake. Personally, real TRIM support (or at least the wiper tool) is the way to go and it sounds like we’ll be getting it for most if not all of these SSDs in the next couple of months. Idle garbage collection worries me."
Bad news about apple SSDs. Remember this article is OLD! Just showing his original attitude towards them. I have no idea whether they use idle garbage collection or not which is why I'm making you do all this reading (sorry) and you can look it up yourself and form your own opinion about whether it's a safe buy. It might actually mention it in the article I'm putting a link to at the bottom (can't remember, I read it ages ago)
"What's Wrong with Samsung?
The largest SSD maker in the world is Samsung. Samsung makes the drives offered by Apple in its entire MacBook/MacBook Pro lineup. Samsung makes the drives you get if you order a Lenovo X300. In fact, if you're buying any major OEM system with an SSD in it, Samsung makes that drive.
It's just too bad that those drives aren’t very good.
This is the 4KB random write performance of Samsung's latest SSD, based on the RBB controller:
4.4MB/s. That's 3x the speed of a VelociRaptor, but 1/3 the speed of a cheaper Indilinx drive.
Speedy, but not earth shattering. Now let's look at performance once every LBA has been written to.
This is the worst case scenario performance we've been testing for the past year:
Now to be fair to Samsung, this isn’t JMicron-terrible performance. It’s just not worth the money performance."
I sorta glanced at the article but didn't bother reading it fully
An issue he had with apple SSD was that it consumed more power than the default Hitachi hard drive, which is actually a big deal because SSDs are meant to run on less power- both when idle and active. He also made a point of saying that since SSDs are more efficient they spend more time idle than they do active and therefore consume even less power than you would expect.
He also mentioned that MacBook Air had an old controller and was limiting. At the top where I showed the most recent mention of SSDs I could find he said the SSDs aren't fast enough and "SandForce anyone?" I think he's taking a stab at whatever their controller is (probably still inferior compared to other SSDs and especially sandforce.
If you're wondering why sandforce is so great:
here's the article on apple SSD:
Sorry but there are actually more things to consider than price and capacity and many different factors you need to consider-there's also garbage collection, TRIM etc. This info is kinda old now and SSDs have advanced, as i said before I have no idea about apples SSDs except that they're expensive and people seem to think finding alternatives are better. Its like apple RAM, same as any other kind except way more expensive, it's not special or anything- (I forgot who makes their RAM).
Anyway this info is just to help you understand what you need to look for/consider when buying SSDs. I hope this helps, sorry for my lack of knowledge but I do have a very general understanding of how SSDs work (sort of) :P and I read through a few of these articles ages ago so I can at least show you the relevant stuff you need to know...
Late to the party, but I've been considering this drive: http://www.storagereview.com/westerndigital_siliconedge_blue_ssdreview
It has internal TRIM support and does not rely on the OS. It is not the fastest drive out there, but at that price, with a 3 year warranty, and a stated lifespan of 5 years writing 43 GB /day this is currently my leading choice.
I wonder it Apple's strategy here will be to fogo TRIM in the OS altogether and only use drives that support it internally?
I am also late to the party. Question, I have a white macbook, late 2007 model and is considering upgrading to an ssd drive. The more research I do the more confuse I get as to what my options are? Any ideas as to what's the best drive for my system? I am looking at the Intel drives- only because of the name recognition. Please help. Thanks