In last month’s column, I mentioned SSDs: specifically, that I think you shouldn’t build a new computer without considering one for storage. This month let’s delve deeper into the current state of SSDs: the tech, the options, and the alternatives. While much of what I’m saying can apply to adding an SSD to an existing computer, my focus here is on the SSD as part of a new build.
Let's Start with a Recap
I’m not going to spend a lot of time running through the nitty-gritty of SSD architecture. The Wikipedia article offers a pretty decent overview. Briefly, a solid state drive is a storage device that stores data on NAND flash memory instead of the spinning magnetic platter that traditional hard drives use. Solid state drives are much faster than traditional hard drives, use less power, and are less prone to mechanical error, because they have no moving parts. They’re fully SATA compatible and (unlike RAM) they retain their data even when disconnected from a power source. They’re designed as drop-in replacements for traditional hard drives, and most come in the same 2.5-inch form factor and with the same SATA power and data connectors as traditional notebook drives, although they’re not limited to that form factor--laptops and some motherboards increasingly include mSATA connectors or (in the case of MacBooks) proprietary connectors. Keep an eye out for that.
A good modern SSD can read large chunks of data at over 500MB per second, write at over 300MB/s, and access random data in .1 milliseconds. The fastest consumer mechanical drives cap at about 150MB/s for sustained sequential reads and writes and 17ms random access time. The difference an SSD makes in your everyday computing can’t be overstated. Windows boots up and resumes faster. Games and programs load in a matter of seconds. Game loading screens become almost a thing of the past. At the same time, your PC consumes slightly less power and puts out less heat and noise and fewer vibrations.
Of course, all this performance has a price: while a mechanical hard drive’s price per gigabyte is frequently under five cents per gigabyte, a good SSD is much more; they only consistently dropped under $1 per gigabyte in 2012. To put it another way: a 250GB Samsung 840 Series SSD is about $170 right now. You can get a 3TB Seagate Barracuda for slightly less--around $140-160.
Have Your Cake and Eat It Too
The best way to get the speed of a solid state drive and the capacity of a mechanical drive is to buy one of each.
If you’re building a desktop, the best way to get the speed of a solid state drive and the capacity of a mechanical drive is to buy one of each. Put your operating system and any games and programs that you run frequently onto the SSD, and use the mechanical drive for music, movies, photos, documents, and any program that you don’t use regularly or don’t mind longer load times in. This option requires a little bit of manual management but offers the best combination of performance and price.
What to look for in an SSD
- 250GB or Larger: If you can, try to get an SSD that’s 250GB or larger. This will give you enough room for Windows and several programs and games without having to constantly micromanage what data is stored where. If your SSD budget is less than $100, you can make do with a 120GB SSD, but if you can swing an extra $50, you should.
- 6Gb/s SATA: If you are building a new rig or adding an SSD to a fairly new machine, you’ll want an SSD with 6Gb/s SATA support (also called Sata 3.0). As the name implies, 6Gb/s SATA (six gigabits per second, or 750 megabytes per second) has twice the theoretical maximum throughput of the last SATA spec, which was 3Gb/s SATA (or SATA II). Running a 6Gb/s SATA SSD on a 3Gb/s port, or a 3Gb/s SATA SSD on a 6Gb/s port, will leave you with a bottleneck, and your read and write speeds will max out at around 250MB/s. A 6Gb/s SATA SSD on a 6Gb/s port will let you run your SSD at the top of its potential.
If your motherboard doesn’t have 6Gb/s SATA ports, you have two options: You can get a 3Gb/s SATA SSD, or you can get a 6Gb/s SATA SSD anyway, and perhaps a PCIe SATA 6Gb/s card. If you’re going to upgrade your motherboard soon, opt for the 6Gb/s SATA SSD so you can use it in your new build.
- TRIM and Garbage Collection: Unlike mechanical drives, SSDs don’t need to be defragmented--and in fact, they shouldn’t be. But if they fill up with data they can still run more slowly than they did when they were new, because of the way data is written to NAND flash. This was a big problem with early SSDs, as performance would decrease dramatically over time, but modern SSDs use garbage collection algorithms to clean up the drive during idle time.
Any modern SSD will have support for TRIM, a command set which is built into Windows 7 and up. This command tells the SSD’s onboard garbage collection which sectors have been deleted in at the OS level, allowing them to be removed during drive idle times. Windows 7 and 8 automatically detect when an SSD is present and enable TRIM while disabling other hard-drive-specific commands such as prefetching and defragmentation.
Know Your Needs, Not Wants
You don’t need an enterprise-level, IOPS-focused solid state drive in your gaming rig. Unless your desktop doubles as a high-traffic web server with a huge database, you’re not going to need 800,000 IOPS at queue depth 32. Even an entry-level SSD at this point is an incredible upgrade over a mechanical drive alone.
Mainstream: Samsung 840 Series SSD. The 840 is Samsung’s move into the entry-level SSD market, and it’s the first consumer SSD to use TLC NAND rather than MLC NAND. AnandTech’s got a great review of the 840, including an analysis of the difference and what it means to you, but the important thing is that the 250GB 840 Series is cheaper and faster than the Crucial m4, which would have been my entry-level recommendation before. You can get a 250GB 840 Series drive for $150 on Amazon right now (a 500GB is $370). That’s cheap enough that you can get two if you’re worried about running out of space.
In my personal rig, I use a 256GB SSD for my OS and programs, and another one for currently installed games. I move games I’m not currently playing (but want to keep around) to my storage drive so I don’t have to re-download the whole thing if I want to reinstall later.
Mid-range: Samsung 830 Series, Corsair Neutron GTX.
Samsung’s 830 Series was a truly excellent solid state drive, recommended by many, including , Anand, Cnet, and myself. They’ve been supplanted by the 840 (slower writes, shorter lifespan, but faster in other respects and cheaper) and the 840 Pro (faster, more expensive), but if you can get your hands on a 256GB Samsung 830 Series for less than $200, do it. Otherwise get a Corsair Neutron GTX. You can get the 240GB Neutron GTX for around $230 at NewEgg.
The Vector is OCZ’s first SSD built with their own Barefoot 3 controller, and it’s truly excellent. Samsung’s 840 Pro is one of the fastest consumer SSDs in every direction. Both run about $270 for a 256GB SSD at this point. The performance advantage of these drives over the Samsung 840 is, in my opinion, not sufficient to justify the price premium for most people. Obviously, if you do a lot of high performance tasks like video editing or modelling and need the increased durability and sustained write speeds, these drives may be worth it, but if you’re just building a rig for gaming and general use you should save the money.
SSD Alternatives: Hybrids and Caching
There are two other ways to add some SSD speed to your rig without getting an SSD boot drive. To be clear, I think the benefits of using a dedicated boot SSD and a secondary mechanical drive outweigh the downsides, but there are alternatives for the dedicated cheapskate. All involve using a small amount of flash storage as a caching device for a larger mechanical drive.
The first alternative is a drive like the Seagate Momentus XT. This is a 750GB mechanical hard drive with 8GB of NAND flash cache. Its onboard controller copies any frequently accessed hard drive sectors to the flash memory, so you will find the things you do all the time, like booting your computer or starting certain programs, soon start functioning as if they’re on an SSD. However, this only applies to stuff you do frequently and only to read operations--you’ll still feel like you’re using a mechanical drive most of the time, because you are.
The second option is a DIY hybrid option using an inexpensive, low-capacity SSD. Recent Intel-based motherboard chipsets include Intel’s Smart Response Technology (SRT), which allows you to use up to 64GB of SSD as a cache for your OS drive, and some motherboards even include an onboard mSATA slot that you can use for this purpose. Many SSD manufacturers now also sell low-cost, low-capacity SSDs specifically designed for caching (e.g. Corsair Accelerator, Crucial Synapse, OCZ Adrenaline). These use third-party software (usually Dataplex) to manage which sectors get written to the drives. This is an okay option if you have an existing hard-drive-based system and you can’t bear to do a clean install onto an SSD, but it has substantial limitations as well. The software only works with MBR partitions, not GPT partitions, so if your OS partition is greater than 2.2TB or was installed while your BIOS was in UEFI mode, you’re out of luck. I’ve learned this the hard way.
Better to buy a fast SSD and put a clean install of Windows onto it than buy a budget caching SSD.
With those options in mind, if you’re adding an SSD to an existing build, I still recommend buying a fast SSD and doing a clean install of Windows onto it and reinstalling your most frequently used programs to that drive, rather than buying a budget caching SSD. The price difference between a 50 or 60GB caching SSD and a 120GB Samsung 840 is less than $20.
Shouldn’t I wait for Price to Plummet?
Well, sure. SSDs are going to be better and cheaper in the future. That’s what always happens with technology, and that’s why we joke that the best time to upgrade your computer is always six months from now. But at some point you need to bite the bullet. I’ve said for years that you should get an SSD if you can, but now I think we’ve reached the point where you shouldn’t build a new rig without one.
The Other Half of the Puzzle
Don’t forget to leave room in your budget for the mechanical drive. You can get a fast 3TB drive (I prefer the one-terabyte-per-platter Seagate Barracuda) for $140 at Amazon right now. There are 4TB drives available, but they’re around $250. You do the math on that one. You can always add a drive later--most motherboards have at least four SATA ports and most cases have at least two 3.5-inch drive bays, and modern ones also have several 2.5-inch drive bays.
If you’re building a new gaming rig, get an SSD. Your best bet, and the combination I personally endorse for most gamers, is to get a 250GB Samsung 840 SSD (~$170) and a 3TB Seagate Barracuda (~140). Your total cost for both will be right around $300. If you need more SSD space for gaming, get another 250GB 840. If you want a faster or more durable SSD because you do a lot of high-performance computing (or you just want the best), get a Samsung 840 Pro or OCZ Vector SSD instead of the Samsung 840.
If you’re adding to an existing build, you should still get the Samsung 840. If your budget’s really tight, get the 120GB version. If your motherboard doesn’t have 6Gb/s ports, get the 840 anyway; “value” SSDs designed for 3Gb/s SATA ports aren’t any cheaper and tend to be slower even on a 3Gb/s SATA port.
Further reading: Anandtech's Samsung 840 Series SSD review