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As written in my first blog article about my Asus EeePC 901Go, there are two different versions of this EeePC model available, one with a very slow SSD and one with a fast SSD.

You can distinguish the two models by looking at P/N on the EeePC box or by opening the EeePC and identifying the SSD itself:

• The slow SSD model has this P/N: 90OA0BTI4214AFNE2X2Q, the SSD is labeled “P2-SSD PS Rev. 2.0G”
• The fast SSD model has this P/N: 90OA0BTI8214AFNE2X2Q, the SSD is labeled “S4-SSD JM Rev. 1.1″

I made sure that I got a fast SSD model, but the question arises:

How fast is it?

Today, I found the time to perform some benchmarks of the SSD read/write speed.

For your information, I’m using two partitions with ext3 filesystem.

One partition contains the Linux base system and the programs and is not encrypted. The other partition keeps my data (including my /home) and is encrypted using Linux’s LUKS infrastructure. I’m using AES 256 bit encryption (aes-cbc-essiv:sha256).

For the test, I created a 512MiB testfile using “dd”.
To avoid biased results because of Linux’s extensive file caching, I’ve rebooted the system after the write command, before doing the read speed test.

Unencrypted write test

che@eee:~$ dd if=/dev/zero of=/unencrypted/ssdtest bs=512k count=1k
1024+0 records in
1024+0 records out
536870912 Bytes (537 MB) copied, 22,7062 s, 23,6 MB/s

Unencrypted read test

eee:~$ dd if=/unencrypted/ssdtest of=/dev/null bs=512k
1024+0 records in
1024+0 records out
536870912 Bytes (537 MB) copied, 6,62449 s, 81,0 MB/s

Encrypted write test (aes-cbc-essiv:sha256)

eee:~$ dd if=/dev/zero of=/crypto/ssdtest bs=512k count=1k
1024+0 records in
1024+0 records out
536870912 Bytes (537 MB) copied, 31,3594 s, 17,1 MB/s

Encrypted read test (aes-cbc-essiv:sha256)

eee:~$ dd if=/crypto/ssdtest of=/dev/null bs=512k
1024+0 records in
1024+0 records out
536870912 Bytes (537 MB) copied, 28,2782 s, 19,0 MB/s

Of course, the performance on the encrypted partition is much slower than on the unencrypted partition. Furthermore, the CPU performs at 100% load when encrypting/decrypting, and that leads to a much shorter battery life. Therefore, I think it’s the best trade-off to only encrypt the data and keep the Linux base system unencrypted.

Conclusion

I’m very happy with the overall speed of my system, the slower performance of the encrypted “/home” is not really noticeable under real work conditions.

In this benchmark, there is of course a big difference between the unencrypted (W: 23.6MB/s, R: 81.0MB/s) and the encrypted (W: 17.1MB/s, R: 19.0MB/s) filesystem.

But remember: To have a secure system, it’s very important to move some directories to the encrypted partition, like:

• /home
• /tmp
• /var/tmp (I’ve moved the whole “/var” to the encrypted partition)

And depending on your system setup:

• /srv
• /var/spool
• /var/cache
• /root
• …everything else that you like to protect from thieves

Furthermore, it very important that you either also encrypt your swap partition or do not use a swap partition at all!

I’ve installed 2GB in the EeePC and do not use a swap. Of course, using a LUKS swap partition with a random key would also be secure.

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For the mobile internet access in Germany, I can recommend these two UMTS providers:

	BASE offers an UMTS flatrate for 17.50€
	Simyo offers a prepaid UMTS solution, 24ct/MB or 10€ for 1GB

I'm using an UMTS card of these providers in the my Asus EeePC 901Go and it works great. Pretty fast and reliable. If you want to order a new UMTS card anyway, please support me by using one of these links. For every order, I get some refund to pay my server bill. Thanks.

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If you like my work, buy me a beer. (Suggested: 3€ for a beer, or more for more beer ;-) )

Tags: EeePC, Gadget, Linux

This entry was posted on Thursday, May 14th, 2009 at 20:45 and is filed under EeePC. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.