Chipset / HDD controller problem on Z77

[robert.badita]

I bought a brand new Z77-D3H board to replace an Intel DZ68DB with a very strange problem: it read/wrote badly from/to the ssd or any hard drive introducing random 1 bit errors to each 1GB read.
The thing is that on this board Z77-D3H it has the same problem. I cannot store on the hard drive backups/archives or any kind of data because it will be read with an error and winrar/zip for example says CRC error or damaged archive.
It is really strange at first I suspected it was the motherboard DZ68DB, but it behaves exactly the same on both boards. I have an i7-2600 cpu and Corsair Vengeance 1600MHz memory.
I've made a small program in .NET4 that creates a file with known data (random looking but deterministic), and when it reads back the same file it signals the differences/errors which look like these:

Error at index 94F117B computed = 9D actual = 99
Error at index 94F18A3 computed = 1A actual = 1E
Error at index 94F1EA3 computed = 8C actual = 88
Error at index D2EF90CB computed = 58 actual = D8
Error at index D2EF917B computed = E7 actual = E3
Error at index D2EF9183 computed = 3C actual = BC
Error at index D2EF92A3 computed = DF actual = DB
Error at index D2EF92E3 computed = 46 actual = 42
Error at index D2EF933B computed = 8C actual = 88
Error at index D2EF954B computed = 4C actual = CC
Error at index D2EF971B computed = 6C actual = EC
Error at index D2EF98A3 computed = 23 actual = 27
Error at index D2EF9D43 computed = EE actual = 6E
Error at index D2EF9EA3 computed = 1D actual = 19
Error at index E370A0A3 computed = 60 actual = 64
Error at index E370ACAB computed = F5 actual = F1
Error at index E370AD73 computed = BC actual = B8
Error at index 1AB8F30CB computed = 2A actual = AA
Error at index 1AB8F316B computed = D3 actual = D7
Error at index 1AB8F3183 computed = 56 actual = D6
Error at index 1AB8F318B computed = AA actual = 2A
Error at index 1AB8F320B computed = 75 actual = F5
Error at index 1AB8F32E3 computed = AE actual = AA
Error at index 1AB8F3CFB computed = 30 actual = 34
Error at index 1AB8F3F3B computed = 34 actual = 30
Error at index 1BC2E20BB computed = D8 actual = DC
Error at index 1BC2E220B computed = B actual = 8B
Error at index 1BC2E2373 computed = 31 actual = 35


I suspect that there's a problem with the Z68 and Z77 chipsets in the sense that they read badly from the hdd (hard disk controller problem) and it can be resolved by software (bios updates). I say this because my older board had absolutely no problem until upgrading the bios to 0040, which cannot be reverted back.
There are high chances that blue screens and freezes are caused by this problem.

EDIT: the RAM is super tested and has absolutely no problem. No overclock. To be able to install windows on Z77-D3H I had to disable cpu C3/C6 states from bios.
The ssd and hard drives work ok on another computer.
Same data integrity errors with Gigabyte bios F8 and F13.

[robert.badita]

Fortunately I've fixed the problem, it was a defective RAM stick - Corsair Vengeance 1600MHz CL9. Though it passed many ram tests (Windows, Prime95, Aida, MemTest).
The original configuration had 16 GB RAM (4 x 4GB). After many tests I identified the defective stick. Now with only 8GB it works very smooth - no errors for 200GB archives tested. With the defective stick in it fails for 10GB.
On short:
 - the defective stick passes many memory tests with no problem.
 - if I insert it in the computer, it completely messes the data that the Z77 and/or Z68 HDD controllers operates on, introducing ugly HDD errors.

I'm glad it's not a motherboard chipset error after all.
The Z77-D3H seems pretty good and stable at first glance.