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Intel 80GB X25-M SSD

Last updated June 01, 2009 - Send Feedback

This is the first semi-mainstream solid state drive to offer top-notch consistent performance.

The X25-M formats to 74.4GB on Mac OS X, where a gigabyte is defined as 1024 X 1024 X 1024.

See also

See the full review of the Intel X25-M solid state drive for more performance data; this drive is screaming fast on anything involving reads; up to 3X the performance of hard drives.

A dual X25-M RAID stripe in the Mac Pro is also a nifty trick.

Fill-volume, MacBook Pro dual X25-M

The graph below shows performance across the drive as it was filled to capacity with 1000 equal-sized files, written 32MB at a time. For more on a dual internal X24-M configuration in a MacBook Pro, see Pimp my MacBook Pro.

Seagate Momentus 7200.3
MacBook Pro 2.93Ghz: dual Intel X25-M drives, RAID stripe
Green is read, red is write

Chunk size results for dual-drive on MacBook Pro 17" 2.93GHz

The dual-drive stripe X25-M disappoints on smaller transfer sizes in this DiskTester test, both for reads and writes, and shows a large variance when tested 1GB at a time (test run twice). The same variance was observed with a single X25-M. This variance was not observed on the 2008 Mac Pro.

However, X25-M sustained performance over the whole drive is excellent however (see above). The reasons for this disparity are unclear, but could have something to do with wear-leveling algorithms.

This variance was not observed on the Mac Pro 2.8GHz in a dual-drive stripe.

# dual-drive internal stripe on MacBook Pro 17" 2.93GHz
------------- Average Writes for "X25x2" (1GB/start, 3 iterations) -------------
Chunk Size Slowest Median Fastest Average Range
32K 56.2 79.9 91.5 75.8 35.3
64K 63.2 65.3 67.2 65.2 4.0
128K 69.2 72.2 77.9 73.1 8.6
256K 73.5 78.3 94.7 82.1 21.2
512K 75.0 76.6 77.7 76.4 2.7
1MB 82.6 94.1 101.9 92.9 19.3
2MB 88.9 91.6 91.7 90.7 2.8
4MB 91.8 100.0 110.6 100.8 18.7
8MB 105.0 106.4 116.9 109.4 12.0
16MB 97.1 101.0 109.2 102.4 12.2
32MB 96.4 108.5 114.4 106.5 18.0
-------------- Average Reads for "X25x2" (1GB/start, 3 iterations) -------------
Chunk Size Slowest Median Fastest Average Range
32K 152 153 162 156 10.8
64K 226 233 238 232 11.4
128K 238 241 244 241 5.8
256K 320 322 329 324 8.6
512K 385 390 406 394 20.6
1MB 428 443 454 442 26.6
2MB 359 407 461 409 101.9
4MB 277 449 469 398 192.2
8MB 200 223 502 308 301.6
16MB 207 365 384 319 177.7
32MB 247 383 516 382 269.0
---------------- Averages for "X25x2" (1GB/start, 3 iterations) ----------------
Chunk Size Write MB/sec Read MB/sec
32K 75.8 156
64K 65.2 232
128K 73.1 241
256K 82.1 324
512K 76.4 394
1MB 92.9 442
2MB 90.7 409
4MB 100.8 398
8MB 109.4 308
16MB 102.4 319
32MB 106.5 382

 

DiskTester results

Test mule: MacBook Pro (Oct 2008 unibody) 2.8GHz 
SATA hardware: internal SATA II connector
Driver: Apple standard
Drive model: SSDSA2MH080G1GC
Get your own copy of DiskTester for testing your drives, RAID, network, etc.

Sequential sustained transfer

Read speeds are simply amazing, blowing away performance from any laptop or desktop hard drive.

Write speeds are very good, and maintained across the entire capacity, unlike hard drives.

# Sequential sustained transfer
----- Averages for "X25" (1GB/start, 3 iterations) -----
Chunk Size Write MB/sec Read MB/sec
32K 52.7 105
64K 55.3 125
128K 58.7 169
256K 60.6 211
512K 62.3 228
1MB 63.5 230
2MB 64.2 238
4MB 64.4 244
8MB 64.3 247
16MB 65.0 249
32MB 64.3 250

Speed across the drive (area test)

Read speeds are unbelievably fast, about 3X faster than the fastest laptop hard drive as of late 2008. Write speeds are quite a bit slower than those of hard drives; the Seagate 320GB Momentus 7200.3 is about 34% faster. These are sequential speeds; any activity involving random access will quickly switch to favoring the X25-M.

Results are shown for 1MB and 32MB transfer sizes.

----- Averages for "X25" (1GB/1MB, 3 iterations) -----
Area (73.0GB) Write MB/sec Read MB/sec
0% 64.1 232
10% 63.9 233
20% 63.4 233
30% 62.5 233
40% 62.9 234
50% 63.1 235
60% 62.7 235
70% 63.2 235
80% 63.0 236
90% 63.5 237
100% 65.8 242
Average write speed across the volume: 63.5MB/sec
Average read speed across the volume: 235MB/sec ----- Averages for "X25" (1GB/32MB, 3 iterations) -----
Area (73.0GB) Write MB/sec Read MB/sec
0% 64.2 256
10% 66.0 258
20% 66.0 258
30% 63.9 258
40% 63.9 261
50% 63.8 259
60% 63.6 259
70% 64.4 260
80% 65.7 261
90% 63.9 261
100% 63.4 261
Average write speed across the volume: 64.4MB/sec
Average read speed across the volume: 259MB/sec

Create and read files

This test times how long it takes to create and flush files to disk, and to read them back, with the Mac OS X cache bypassed so as to reflect actual hard drive performance. The test is run on empty freshly-formatted drive.

This test shows speeds about 40% slower than the speedy Seagate 320GB Momentus 7200.3, While the Momentus slows down as it fills up (as all hard drives do), it will still be about 21% faster at the nominal 80GB mark (74.4GB formatted).

disktester create-files / read-files
Action Time (seconds) MB/sec
Create 5120 1MB files 84.4 60.6
Read 5120 1MB files 23.5 217.9
Create 512 10MB files 84.9 60.3
Read 512 10MB files 22.0 232.7

With the advent of “stutter” in mediocre solid state drives, it’s not a bad idea to look at the consistency of performance, easily visualized here. The X25-M offers nicely consistent performance (512 files totaling 5GB).

Seagate Momentus 7200.3
Variance of 10MB file creation times (ms)
 


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