X-bit labs

27 Card Readers Roundup (page 8)

Category: Multimedia

by Aleksey Meyev

[ 03/23/2008 | 11:11 AM ]

Intel IOMeter Disk Response Time

The average read/write response time is measured in a 10-minute test to read/write 512-byte data blocks with a request queue of 1. The reader has to process over 60,000 requests, so we get a sustained response time as the result. The numbers are sorted by read response.

The readers have similar results here. The difference between the worst and best result is a mere 3%. The read response time is very small especially in comparison with other types of storage (for example, hard disk drives). The AU6377 is again the best controller. It is followed by the AU6362 (with firmware 01.00 while the other firmware versions are slower), the GBL819 with both firmware versions, and SanDisk Extreme USB.

Intel IOMeter Random Read and Write

I’ll evaluate the speed of random read and write operations by measuring the time the readers take to perform them. The data block size is varied from 0.5 to 8192KB in this test.

I don’t build a diagram for this test – the table is enough. It’s clear that the controllers line up in the order of their results in the sequential reading test. The AU6377 is first, and most other controllers follow it in a dense group. The AU6263 with the “slow” firmware versions is last, and the ND3260 and IC1210 are rather slow, too.

There are no significant changes when we change reading for writing.

Intel IOMeter Windows Vista ReadyBoost

We continue checking out external storage media for their compliance with Windows Vista’s ReadyBoost technology using IOMeter. To remind you, the point of that technology is in using a flash drive or a flash card as an additional cache with a data access time lower than that of the hard disk. To qualify for this application, the external disk must meet certain performance requirements and have a capacity of 256MB and higher. The OS itself benchmarks the speed of the attached device and proposes that it be used for ReadyBoost. What are the requirements? The flash disk must ensure a data-transfer rate of 2.5MB/s and higher when reading random 4KB data blocks and a data-transfer rate of 1.75MB/s and higher when writing 512KB data blocks. So, we measure these two speeds in a 10-minute test. For better readability, the red vertical line marks the ReadyBoost-compliant speed in the diagrams:

Only the slowest readers – the AU6332 and ND3250 – cannot pass this test when working with the fast CF card. The IC1210 was very close to a failure as well, yet it passed the test. The other readers coped with the task easily.

The requirement of 1.75MB/s proved to be easy for each reader. This test is more demanding about the card’s speed on small data blocks rather than to the controller’s capabilities. To remind you, a SanDisk Ultra II card couldn’t pass this test in any reader.