Overclock the Kurobox Pro/Linkstation Pro
Disclaimer and Preface
Use this at your own risk, as it can potentially brick your Linkstation
The credit goes to the author of the original Japanese article, of which this procedure is based on. (http://www.google.com/translate?u=http%3A%2F%2Fkurobox.jp%2Fkuroweb%2F&langpair=ja%7Cen&hl=en&ie=UTF8)
Since I have successfully done the modifications of my LSPRO and like to share my experience to make up the deficiency of Google translate and the changes (compare to the original article) I have to make to get it to work. I believe the reason for the changes is possibly due to the original article was on a Kuro Pro, whereas mine is a LSPRO. The photo of the board shown in the original article also looks different too, possibly due to different board revision.
The ARM CPU used is the LSPro is rated at 500Mhz but was underclocked to 400Mhz for marketing or other reason (I beleive). This mofication is to add a 500Mhz clock source allowing the CPU to run at it's rated speed, where as other clock remains unchange. Straightly speaking, this is not an overclock.
As at time of writing of this article, it is less than 24 hours since the modification has been done, I am not absolutely sure if there will be any stability or reliability issue due to the changes I have done and only time can tell.
I will update this post with more pictures in the next few days and results on liability in weeks to come. While I already have my LS pull apart, I like to do the hack for second SATA connector with another drive connected with intent to make it function similar to the Duo. Until then, hopefully in a week’s time, I will not be able to put it under stress test.
In my opinion, you need good soldering skill and access to a good fine tip soldering iron or station.
- 3.3V, 31.25Mhz (giving 500Mhz CPU clock) SMT (surface mount) oscillator module. The closes you can get off the shelf is 32Mhz (giving 512Mhz CPU clock), which works well in my modification. I bought this from RS Component, p/n 471-9427 for AUS$9.60. http://www.rsaustralia.com/cgi-bin/bv/rswww/searchBrowseAction.do?N=0&Ntk=I18NRSStockNumber&Ntt=471-9427&Nty=1&D=471-9427&callingPage=/jsp/line/line.jsp&BV_SessionID=@@@@0050679339.1204691026@@@@&BV_EngineID=cccladedhgehlhfcefeceeldgkidhgn.0&cacheID=auie&Nr=avl:au
- 0.1uf SMT Capacitors x 2.
- SMT high frequency filter. (I don’t have the value; it is used for high frequency filtering in the 3.3 v DC supply for the oscillator module). Alternatively (in my opinion, although I have not tried it myself) a jumper wire or 10 ohm resistor will do the job, if you are unable to find a RF filter.
- 1 inch length of fine jumper wire or wire wrapping wire.
You should be able to find items 2 -3 in any old PC cards or motherboard, and I got them from an old LinkSys VOIP adaptor (SPA3000).
Please refer to the original Japanese translation and pictures if required, steps used here follows the original Japanese article.
Before the actual modification you need to remove motherboard from LS by following the disassemble procedure in this WiKi (http://buffalo.nas-central.org/index.php/Disassemble_the_LS_Pro_v1/LS_Live_v1), allowing you to do the soldering on a work bench.
Work area is to left of existing oscillator module X2.
Install crystal oscillator module (item 1 in parts list) to X3 position.
C221 does not exist in the motherboard position as shown in the original photo or article; you can ignore it for the moment. Will re-visit in step 5.
Move resistor R238 to resistor position R165.
Pin out of oscillator module for reference: • #1 OE • #2 GND • #3 CLK OUT • #4 VCC(3.3)
This is the step I got caught, picture shown in the Japanese article is different from the layout on my LS PCB, and the LS failed to power up (keep beeping)the first time without this change.
Work area is to right next to oscillator X3 installed at Step 1.
The original article is to move R237 to R249, where R237 exist but not R249 in my LS motherboard.Instead I moved R237 to R183.
Solder jumper wire (item 4 in parts list) connecting Pin 3 on X2 (25M oscillator module) to Pin 3 on X4 (Nothing was soldered, only just the solder pad). This step is not in the original Japanese article, change I have to make by educated guess to make the LS power up.
Work area is to left of ARM CPU, be careful as Resistor label is not next to physical location.
Move R50 to R78.
Work area is on other side of the PCB behind the ARM CPU.
Move R54 to R82.
Work area is on other side of PCB where X3 oscillator module was added in step 1.
Original article mention add C227, which is already installed in place.
Add by soldering C222 and C221 with SMT capacitor (item 2 in parts list).
Add by soldering FIL4 with filter or jumper wire (item 3 in parts list).
Put all back together
Reassemble motherboard back to chassis, re-connect hard disk and assemble case in reverse order of disassemble. You may prefer to test if it works before complete re-assembly of LS. Test with the utmost caution, as any accidental short may brick your box. To confirm if the LS CPU is running at 500M, you can SSH into the LS, a type "less /proc/cpuinfo", the BogoMIPS should read aroung 340.78 (512Mhz) instead of 266.24 (400Mhz).
Also, for peace of mind, you may want to consider attaching a heat sink to the CPU. Be mindful of the height of the heat sink that may hit the hard drive.