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IO testing, SSD versus SAS

Updated on Mon, 2010-05-10 12:55 by testadmin. Originally created by jeromel on 2010-05-10 09:14.

The expected SSD performances are added below for guidance. The tests were performed by Bonnie++ using the same parameters for bo the SSD and SAS drives.

  Sequential Output Sequential Input Random
Seeks		   Sequential Create Random Create
IO Test
 		 Size:Chunk Size Per Char Block Rewrite Per Char Block   Num Files Create Read Delete Create Read Delete
K/sec % CPU K/sec % CPU K/sec % CPU K/sec % CPU K/sec % CPU / sec % CPU   / sec % CPU / sec % CPU / sec % CPU / sec % CPU / sec % CPU / sec % CPU
SAS unbuffered 24008M 65219 79 61731 8 38486 3 80270 97 102747 2 454.1 0 16 2741 2 +++++ +++ 2464 2 2094 2 +++++ +++ 2155 1
SAS buffered 24008M 62152 75 70581 9 35703 2 79801 96 102588 2 404.9 0 16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++
SSD unbuffered
 24008M 84946 99 202446 29 96371 8 80093 97 241789 5 10776.6 24 16 3821 4 +++++ +++ 3321 3 3665 4 +++++ +++ 3361 2
SSD buffered 24008M 78445 93 217912 30 95316 8 80561 97 239522 5 12778.4 30 16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++

 

SAS Technical specifications

Vendor technical sheets for the 3 Gb/sec SAS interface and the drive used (the Fujitsu MBC2073RC) indicates performance as below:

FUNCTIONAL SPECIFICATIONS
Formatted storage capacity 73.5 GB
Seek time (track to track) Read 0.2 / Write 0.4 ms. typ.
Seek time (average) 3.0/3.5 ms. typ. (read/write)
Seek time (full track) 6.0/7.0 ms. typ. (read/write)
Average latency time 2.00 ms.
Rotational speed 15,000 RPM
Interface SAS (3Gbps) 
Data Buffer Size 16 MB
Recording code 60/62 MEEPRML 
Head positioning method ROTARY VCM 
Spindle start time 15 seconds typical
Spindle stop time 15 seconds typical

None of the technical sheet would provide IO rates but only seek and access time latencies.

Pricing for a 73.5 GB, 15k RPM drive is ~ 160$ hence a cost of 2.2 $/GB.

 

SSD Technical specifications

The specifications for the Intel® X25-E Extreme SATA Solid-State Drive, a 64 GB are given on the Web and copied below.

Model name

Intel® X25-E Extreme SATA Solid-State Drive

Capacity

32GB and 64GB

NAND Flash components

Intel® Single-Level Cell (SLC) NAND Flash Memory
10 Parallel Channel Architecture with 50nm SLC ONFI 1.0 NAND

Bandwidth

Sustained sequential read: up to 250 MB/s
Sustained sequential write: up to 170 MB/s

Read latency

75 microseconds

I/O Per Second (IOPS)

Random 4KB Reads: >35,000 IOPS
Random 4KB Writes: >3,300 IOPS

Interface

SATA 1.5 Gb/s and 3.0 Gb/s

Form factor

2.5" by 7mm industry standard hard drive form factor

Compatibility

SATA Revision 2.6 Compliant. Compatible with SATA 3 Gb/s with Native Command Queuing and SATA 1.5 Gb/s interface rates

Life expectancy

2 Million Hours Mean Time Before Failure (MTBF)

Power consumption

Active: 2.4W Typical (server workload¹)
Idle (DIPM): 0.06 W Typical

Operating shock

1,000G / 0.5ms

Voltage

5V SATA supply rail

Operating temperature

0°C to +70°C

RoHS compliant

Meets the requirements of EU RoHS Compliance Directives

Product health monitoring

Self-Monitoring, Analysis and Reporting Technology (S.M.A.R.T.) commands, plus additional SSD monitoring

 

Pricing is given by the graph below - in green the lowest price found across all vendors and the blue, the median.

 

The price trend hence indicates a low is ~ 10 $/GB (pricing is a factor of ~ 5 comparing to a performing drive).

 

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