The SSD Anthology: Understanding SSDs and New Drives from OCZ
by Anand Lal Shimpi on March 18, 2009 12:00 AM EST- Posted in
- Storage
Simulating a Used Drive
Since SSD performance degrades over time, it’s important to not only look at how well these drives perform new - but also the worst they’d perform over their lifetime. In order to do so we’d need a repeatable way of “seasoning” a drive to reduce its performance to the worst it could possibly get. The most realistic worst-case scenario is one where every single block on the drive is full of data. If a secure erase wipes all LBAs, that’s the best place to start. To simulate a well seasoned drive I first secure erased the drive.
After the secure erase, I used iometer to write one contiguous file across the disk - filling up the entire drive with 128KB blocks. In the case of the 80GB Intel X25-M, that’s 74.5GB of data on the drive before I run a single benchmark. The spare area is left untouched.
Next, I take my test image and I restore it onto the partition with a sector by sector copy. The sequential file write made sure that data is stored in every page of the SSD, the test image restore adds a twist of randomness (and realism) to the data.
There are other ways to produce a drive in its well-used state, but this ends up being the most consistent and repeatable. To confirm that my little simulation does indeed produce a realistically worn drive I ran PCMark on three different drives: 1) a freshly secure-erased Intel X25-M, 2) an Intel X25-M setup using the method I just described and 3) the Intel X25-M used in my CPU testbed that has been through hundreds of SYSMark runs.
The benchmark of choice is PCMark Vantage; it simulates the real world better than most drive benchmarks. The results are below:
| Intel X25-M State | PCMark Vantage Overall Test | PCMark Vantage HDD Test |
| Fresh Secure Erase | 11902 | 29879 |
| Simulated Used Drive | 11536 | 23252 |
| Actual Testbed Used Drive | 11140 | 23438 |
The secure erased system loses about 3% of its overall performance and 22% of its hard drive specific performance compared to my testbed drive. The seasoning method I described above produces a drive with nearly identical drops in performance.
The method appears to be sound.
Now that we have a way of simulating a used drive, let’s see how the contestants fared.
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matrixireland - Thursday, December 24, 2009 - link
hi would like to know what you pros think of the;Golden Leopard ASAX-ZIF1.8-SSD? what would you add to it?
And how would you rate it against other ssd?
Specifications:
product description
ASAX-ZIF1.8-SSD is a high-performance design solid state drive based on the high-end micro-control IC with flash memory storage medium integrated advantaged of high speed,convenient ,aseismatic,energy-saving etc.
specification
Model
Size
Interface
Material
ASAX-ZIF1.8-SSD
1.8inch 70×54×6mm
ZIF
Aluminum-magnesium alloy appearance ,drawbench and colorful oxidation surface,elegant temperament
performance
read speed:80- 96Mbytes/second write speed:50- 60Mbytes/second
support ATA-7 V3 PIO/multi word/ultra DMA MODES
Low power TFBGA,4 channel of flash controller,masked ROM and data SRAM
SAMSUNG flash keeps the data faster on reliability and endurance
Dynamic and static wear-leveling prolong NAND FLASH and SSD for longer life
8/16 bit BCH ECC data error correction ability effectively guarantee the data read security.
Design consideration
Capacity
16G/32G/64G/128G/256G
Average access time
<0.25MS
operating temperature
0-85°
power consumption
DC Input Voltage(3.3V or 5 V ± 10%)Read and write:135mA/194Ma wait:70mA
shock
1500G
Application
the Laptop, pc, server,workstation,portable media player,digital collection apparatus and any computer equipment which need consecutive read and write speed and high reliability storage.
jay401 - Wednesday, March 18, 2009 - link
yeah, he wants "more expensive than" or "too expensive for".Spoelie - Wednesday, March 18, 2009 - link
Second page as well:missing charts before and after this paragraph:
"The chart above shows how much faster these affordable MLC SSDs were than the fastest 3.5” hard drive in sequential transfers. But now look at random write performance:"
Spoelie - Wednesday, March 18, 2009 - link
chart 1 on page 2 now shows sequential read but the paragraph is changed to mention random read ;)page 21: As far as I know, this is THE one of THE only reviews
Some very surprising benchmark results for the ocz vertex, I thought the new firmware tanked sequential read speeds (to 80-90) based on the explanation beforehand, but not according to the actual graphs.
Spoelie - Wednesday, March 18, 2009 - link
third page, first table, first column: SSD and HDD entries are switchedmikaela - Tuesday, March 16, 2010 - link
yeah great info. also great resourceSpoelie - Wednesday, March 18, 2009 - link
page 19: I’d never reviewed it'd & -ed?
HolyFire - Wednesday, March 18, 2009 - link
"I'd never reviewed it" is correct. "I'd" here means "I had", it's Past Perfect tense.FishTankX - Wednesday, March 18, 2009 - link
That should have bolded "too"FishTankX - Wednesday, March 18, 2009 - link
Also, I think the velociraptor vs X-25 figures are swapped. 6 odd ms for the intel drive and 0.11ms for the velociraptor..