The difficulty with calculating by hand is there are some checksum bits. If your goal is to overclock the ram to maximize its performance, you probably have to do it again and again for servel times so that the ram reaches its best performance without failing the memtest (the higher the speed the more likely to fail the memtest). Without a tool or a script the checksum bits has to be calculated everytime by hand...I am calling for a tool to make this eaiser...
Possibly you don't need to invest extra money (but just some time) to use that tool. Thaiphoon Burner has a free version that it does not allow you to save the spd.bin but it has a hex editor that can show you the modified hex bits and the calculated checksum. It can be used as a reference. Then manually modify the spd.bin file and write it using some free tools (e.g., RWEveryting on Windows or eeprom/i2c-tool on Linux).
2016-12-17 5:21 GMT+08:00 David Hendricks firstname.lastname@example.org:
On Fri, Dec 16, 2016 at 11:01 AM, Pok Gu email@example.com wrote:
Thaiphoon Burne is the most popular and probably the only tool for modifying the spd.bin. It has many built-in templates and you only need to select the speed, clocking, and voltage you like (e.g., DDR3-1688/DDR3-1333 and CL10/CL11 and 1.35V/1.5V) and it will do all the rest calculations and generate the spd.bin for you. Then, the only thing you need to do is to flash the spd.bin to the spd chip on the ram, and reboot, and your ram stick is overclocked.
Unfortunately, it is only available on Windows. So I have one harddisk loaded with Windows 7 and Thaiphoon Burne specialized for this work.
I haven't found any linux software can do this unless you calculate and modify the spd.bin by hand. (If anyone found one let me know)
Cool - I never knew about that tool. Seems like a good investment if the goal is to generate an spd.bin from scratch.
Sebastien - What are you trying to do, exactly? If you only need to change one or two parameters, then a hex editor and a calculator should be sufficient. The relevant specification for SPDs is JEDEC Standard No. 21-C Annex K for DDR3 and Annex L for DDR4. (you'll need to register with jedec.org to download the specs)
-- David Hendricks (dhendrix) Systems Software Engineer, Google Inc.