HDD x2?

Hard disks, SSD, SATA interface, external HDD
yogev_ezra
Posts: 539
Joined: Sun Mar 22, 2009 2:49 pm

Re: HDD x2?

Post by yogev_ezra »

Very nice, but:
1) The info on the page is only in German - can you provide an English version?
2) How is the hard disk power connected to your extender board?
3) What is the estimated price? (sample and volume order)

web733
Posts: 5
Joined: Mon Jun 21, 2010 5:00 pm

Re: HDD x2?

Post by web733 »

Hello!
1. The web page is now also available in English.

2. There are two SATA power cables included. You can cut it to the right length and put it into the clamp from the extender board. Its very easy.

3. One sample would cost 139 Euros. For volume order i could offer you a better price, but this would depend on the quantity ordered.

Image

yogev_ezra
Posts: 539
Joined: Sun Mar 22, 2009 2:49 pm

Re: HDD x2?

Post by yogev_ezra »

Thank you very much for the English version! Now it's much better understandable.

The only problem I see is with very high price (half the price of Fit-PC2 itself). Commell MPX-3132 is about 50$. I agree that your design provides all-in-one solution, but for 3 times the price. I wonder what would be the price for volume orders (20+ units).

PieterPan
Posts: 29
Joined: Sat Jan 02, 2010 9:39 pm

Re: HDD x2?

Post by PieterPan »

I've finally ordered the MPX-3132, it was 40 euro's including shipping in Holland. I also ordered two Samsung Spinpoint F4 EcoGreen 2TB 5400rpm drives for storage.

I might power these with an adapter I had laying around (combined 5 and 12v, it says it can provide 1.5A on 5V and 1.8A on 12V). However I doubt that this is enough for the spin up current, so I'll need to do more research on it. The drives say 2A max spin up current, but not on which lines. Otherwise I will use a normal PC power supply for 12v for the fit-pc, and the two harddrives.

I will use this with my fit-pc2 using Ubuntu on the 2.5" internal harddrive. I'm not sure if I will use a raid configuration, or just use linux LVM.

I will provide an update on how this performs, also over the Gb network.

yogev_ezra
Posts: 539
Joined: Sun Mar 22, 2009 2:49 pm

Re: HDD x2?

Post by yogev_ezra »

Success with your mod, would love to see your progress :)

PieterPan
Posts: 29
Joined: Sat Jan 02, 2010 9:39 pm

Re: HDD x2?

Post by PieterPan »

I made some time today to work on the mod. It turned out quite well actually. I was able to use an old power supply for an external harddrive to power the fit pc and two drives. I think it can deliver 12V@1.8A and 5V@1.6A. It is probably a bit stressed when the drives spin up, but it seems to work fine anyway.
The great thing is that when the drives and the fit-pc are running, it uses a total of 18 watts! Definitely below the limits of the power supply. (if I can believe the cheap power meter I have). Before I connected everything to a pc power supply, but it used over 30 watts.

I just cut out some space for the cables to go, looks quite tidy. I did have to remove the shrinktube around the sata cable, I taped it with a bit of clear tape to be safe.

So I now have a fit-pc with 4.3 TB of storage using 18 watts :) I still have to format the drives and set up a volume group. I was able to test some basic hdd performance (using hdparm -t /dev/sda), I get about 73 mb/s, whereas the internal one was stuck at about 60 mb/s. I doubt I will reach that much on the network, so I'm satisfied.

Next project is to build a simplistic case for the server, but that's later.
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yogev_ezra
Posts: 539
Joined: Sun Mar 22, 2009 2:49 pm

Re: HDD x2?

Post by yogev_ezra »

Very nice, although I would try to find a better power supply - I am afraid the hard disks could be damaged because their spin-up current is higher than the max. current your adapter can provide...

PieterPan
Posts: 29
Joined: Sat Jan 02, 2010 9:39 pm

Re: HDD x2?

Post by PieterPan »

You are probably right. For now it is running fine, I'm quite sure that when the drives are at speed, the current draw will be ok. I just shouldn't turn it off :)
Soon I'll get one of those combined 2A@5V + 2A@12V adapters. This will work fine for both drives spinup current. The Fit-PC doesn't start up automatically, so I just wait until the drives have spun up, and then start the Fit-PC. Both drives running together uses about 10W, so I cannot hit either 5V or 12V limit. Heck, the whole thing together doesn't use much more than 20W, of which around 6-8W goes to the 12V on the Fit-PC.

To follow up on the performance: I can get about 60-70 MB/sec over samba to a windows 7 machine. Keep in mind that you do need Jumbo frames (ifconfig eth0 mtu 7000 in ubuntu) and also in windows (property tab of network adapter).
I'm happy with the results. I might try to overclock the fit-pc a bit to see if the performance increases more. It looks like it is CPU bound...

yogev_ezra
Posts: 539
Joined: Sun Mar 22, 2009 2:49 pm

Re: HDD x2?

Post by yogev_ezra »

Many users reported that when you overclock, LAN stops working. I really hope that in your copy of Fit-PC2 it will not happen, otherwise overclock would be pointless for you.

For the custom chassis, I can suggest you a broken internal PC power supply. Take out all the power switching circuitry and you have a nice aluminum case in which you can put both 3.5" disks and the Fit-PC2.

PieterPan
Posts: 29
Joined: Sat Jan 02, 2010 9:39 pm

Re: HDD x2?

Post by PieterPan »

Thanks for the tips, maybe I'll just be happy with the current speeds. Better than usb2.0 :)
Regarding the case suggestion, it might work, but the harddrives with the sata cables are 16 cm long, so I might have to do a little modding. Thanks!
Edit: I could always add a small 12V fan, attached to the 5V power lines for cooling, in open air the harddrives are reaching 40. Or I could keep the 12V fan from the psu itself, if there is space, and attach it to 5V.

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