Dueling firmware revisions
This review would have been published earlier had we not encountered slower than expected performance in some of our used-state tests. We pinged Samsung and learned that new firmware was on the way to address a performance drop with "dirty" drives. That updated firmware is now out for both the 840 Series and the 840 Pro—revisions DXT07B0Q and DXM04B0Q, respectively—and we have test results for each drive with its shipping firmware and the new rev.
Interestingly, the new firmware revisions are sort of a step back. Samsung changed its TRIM policy for the 840 family, an adjustment that lowered write performance for drives that had been filled to capacity. In the latest firmware spins, the TRIM policy has reverted to match the behavior of the 830 Series.
As it turns out, the 840 family suffered a more serious firmware issue before the drives were released to the general public. The samples initially sent out to reviewers had pre-production firmware that failed to update the metadata correctly after a secure erase, causing drives to meet an early demise in certain circumstances. This early firmware was confined to media and engineering samples, Samsung says, and the problem was fixed in the firmware installed on drives sold to consumers. We haven't seen any reports of premature failures with production drives, so it looks like Samsung was successful in nipping that issue in the bud.
Our testing methods
If you're familiar with our test methods and hardware, the rest of this page is filled with nerdy details you already know; feel free to skip ahead to the benchmark results. For the rest of you, we've summarized the essential characteristics of all the drives we've tested in the table below. Our collection of SSDs includes representatives based on the most popular SSD configurations on the market right now.
|Corsair Force Series 3 240GB||6Gbps||NA||SandForce SF-2281||25nm Micron async MLC|
|Corsair Force Series GT 240GB||6GBps||NA||SandForce SF-2281||25nm Intel sync MLC|
|Corsair Neutron 240GB||6GBps||256MB||LAMD LM87800||25nm Micron sync MLC|
|Corsair Neutron GTX 240GB||6GBps||256MB||LAMD LM87800||26nm Toshiba Toggle DDR|
|Crucial m4 256GB||6Gbps||256MB||Marvell 88SS9174||25nm Micron sync MLC|
|Intel 320 Series 300GB||3Gbps||64MB||Intel PC29AS21BA0||25nm Intel MLC|
|Intel 335 Series 240GB||6Gbps||NA||SandForce SF-2281||20nm Intel sync MLC|
|Intel 520 Series 240GB||6Gbps||NA||SandForce SF-2281||25nm Intel sync MLC|
|OCZ Agility 4 256GB||6Gbps||512MB||Indilinx Everest 2||25nm Micron async MLC|
|OCZ Vector 256GB||6Gbps||512MB||Indilinx Barefoot 3||25nm Intel sync MLC|
|OCZ Vertex 4 256GB||6Gbps||512MB||Indilinx Everest 2||25nm Intel sync MLC|
|Samsung 830 Series 256GB||6Gbps||256MB||Samsung MCX||27nm Samsung Toggle MLC|
|Samsung 840 Series 250GB||6Gbps||512MB||Samsung MDX||21nm Samsung Toggle TLC|
|Samsung 840 Pro 256GB||6Gbps||512MB||Samsung MDX||21nm Samsung Toggle MLC|
|WD Caviar Black 1TB||6Gbps||64MB||NA||NA|
We used the following system configuration for testing:
|Processor||Intel Core i5-2500K 3.3GHz|
|Motherboard||Asus P8P67 Deluxe|
|Platform hub||Intel P67 Express|
|Platform drivers||INF update 188.8.131.520
|Memory size||8GB (2 DIMMs)|
|Memory type||Corsair Vengeance DDR3 SDRAM at 1333MHz|
|Audio||Realtek ALC892 with 2.62 drivers|
|Graphics||Asus EAH6670/DIS/1GD5 1GB with Catalyst 11.7 drivers|
|Hard drives||Corsair Force 3 Series 240GB with 1.3.2 firmware
Corsair Force Series GT 240GB with 1.3.2 firmware
Crucial m4 256GB with 010G firmware
Intel 320 Series 300GB with 4PC10362 firmware
WD Caviar Black 1TB with 05.01D05 firmware
OCZ Agility 4 256GB with 1.5.2 firmware
Samsung 830 Series 256GB with CXM03B1Q firmware
Intel 520 Series 240GB with 400i firmware
OCZ Vertex 4 256GB with 1.5 firmware
Corsair Neutron 240GB with M206 firmware
Corsair Neutron GTX 240GB with M206 firmware
Intel 335 Series 240GB with 335s firmware
Samsung 840 Series 250GB with DXT06B0Q, DXT07B0Q firmware
OCZ Vector 256GB with 10200000 firmware
Samsung 840 Pro Series 256GB with DXM03B0Q, DXM04B0Q firmware
|Power supply||Corsair Professional Series Gold AX650W|
|OS||Windows 7 Ultimate x64|
Thanks to Asus for providing the systems' motherboards and graphics cards, Intel for the CPUs, Corsair for the memory and PSUs, Thermaltake for the CPU coolers, and Western Digital for the Caviar Black 1TB system drives.
We used the following versions of our test applications:
- Intel IOMeter 1.1.0 RC1
- HD Tune 4.61
- TR DriveBench 1.0
- TR DriveBench 2.0
- TR FileBench 0.2
- Qt SDK 2010.05
- MiniGW GCC 4.4.0
- Duke Nukem Forever
- Portal 2
Some further notes on our test methods:
To ensure consistent and repeatable results, the SSDs were secure-erased before almost every component of our test suite. Some of our tests then put the SSDs into a used state before the workload begins, which better exposes each drive's long-term performance characteristics. In other tests, like DriveBench and FileBench, we induce a used state before testing. In all cases, the SSDs were in the same state before each test, ensuring an even playing field. The performance of mechanical hard drives is much more consistent between factory fresh and used states, so we skipped wiping the HDDs before each test—mechanical drives take forever to secure erase.
We run all our tests at least three times and report the median of the results. We've found IOMeter performance can fall off with SSDs after the first couple of runs, so we use five runs for solid-state drives and throw out the first two.
Steps have been taken to ensure that Sandy Bridge's power-saving features don't taint any of our results. All of the CPU's low-power states have been disabled, effectively pegging the 2500K at 3.3GHz. Transitioning in and out of different power states can affect the performance of storage benchmarks, especially when dealing with short burst transfers.
The test systems' Windows desktop was set at 1280x1024 in 32-bit color at a 75Hz screen refresh rate. Most of the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.