# Where is my problem with the speed of geli



## Katakuna (Nov 9, 2010)

Hi,

I've a small file server (Duron 1400, 1 GB RAM) with a IDE drive for FreeBSD 8.1 and 2 mirrored SATA drives on a Netcell Revolution RAID card, which are encrypted with geli. I followed the instructions in the handbook closely to create the encrypted partitions. At least I think i did...

The write performance of the IDE drive is about 2 times the performance of the geli device (9.5 Mb/sec), which seems a bit strange to me. But I'm a beginner regarding FreeBSD and geli, so may be this is already the fastest it can work, but may be I made a mistake and hopefully you can help.

I did `geli list` and think there may be a problem with different sector sizes:


```
Geom name: ad4.eli
EncryptionAlgorithm: AES:CBC
KeyLength: 256
Crypto: Software
UsedKey: 0
Flags: BOOT
Providers:
1. Name: ad4.eli
Mediasize: 1000204881920 (932G)
Sectorsize: 4096
Mode: r1w1e1
Consumers:
1. Name: ad4
Mediasize: 1000204881920 (932G)
Sectorsize: 512
Mode: r1w1e1
```

Is this a problem regarding performance? If so, can I change the sector size of the consumer without loosing the data on it? I' don't have enough space to back up the data at the moment, but if this is the only option I'll find a way. 

Any help is appreciated!


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## Galactic_Dominator (Nov 9, 2010)

I don't think anything is going to help short of upgrading the cpu.  Disk encryption puts an large CPU overhead on the system.

You can verify you are CPU bound by watching `% top` during a benchmark.


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## Katakuna (Nov 10, 2010)

Thanks, I'll do that test. Hints like this are very valuable for a newbie!

Is it worth trying to use a via c3 800? It has a built-in AES engine, as far as I know. May be despite the otherwise slow cpu this might be fast enough?
If not, what kind of cpu should I use instead? Should be as energy efficient as possible, may be an Athlon X2 EE?


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