Re: TRULY Custom RAM Timings for GPU's with GDDR5

Original Samsung 4G ( your particular GPU ) 1625
555000000000000022CC1C00CE596B44D0570F1531CB2409004AE700 [ 0B03 | 1420 ] 7A8900A003000000170F2E36922A3217

Quote

--> MC_SEQ_MISC1
-- MR0
   WL = 3, CL = 22, TM = 0, WR = 23, BA0 = 0, BA1 = 0, BA2 = 0, BA3 = 0
-- MR1
   DS = 0, DT = 1, ADR = 1, CAL = 0, PLL = 0, RDBI = 0, WDBI = 0, ABI = 0,
   RES = 0, BA0 = 0, BA1 = 1, BA2 = 0, BA3 = 0

Original Samsung 4G 1750
777000000000000022CC1C0010626C49D0571016B50BD509004AE700 [ 1405 | 1420 ] 7A8900A003000000191131399D2C3617

Quote

--> MC_SEQ_MISC1
-- MR0
   WL = 4, CL = 23, TM = 0, WR = 25, BA0 = 0, BA1 = 0, BA2 = 0, BA3 = 0
-- MR1
   DS = 0, DT = 1, ADR = 1, CAL = 0, PLL = 0, RDBI = 0, WDBI = 0, ABI = 0,
   RES = 0, BA0 = 0, BA1 = 1, BA2 = 0, BA3 = 0

I think you are off by +1 with the MR0 CAS latency. SEQ_CAS_TIMING has CL=21(0x15) for the 1625 strap, and CL=22(0x16) for the 1750 strap.

Excuse my ignorance, but where is a 22 or 21 on 0x2014030B, or a 23 or 22 on 0x20140514 ?
22 binary is 10110, 21 binary is 10101, 23 binary is 10111, none of those patterns are in any of those two numbers... what am i missing?

The CAS latency in MR0 is just four bits (A3-A6), so it is based on a table lookup. H5GQ1H24AFR supported all possible latencies from 5 to 20. Micron's EDW4032BABG brief says "Programmable CAS latency: 627", so some latencies in the range cannot be programmed. I don't have a Samsung datasheet for the K4G4 series (or any Samsung for that matter), so I would have to reverse-engineer the values from the straps by comparing the MR0 values to CL from SEQ_CAS_TIMING.

Timings samsung k4g80325FB

2000 777000000000000022CC1C0031F67E57F05711183FCFB60D006C070124081420FA8900A00300000 01E123A46DB354019
   tcl: 24=>25 - MISC1: 0x20140824 0010 0000 0001 0100 0000 1000 0010 0100

1750 777000000000000022CC1C00106A6D4DD0571016B90D060C006AE70014051420FA8900A00300000 01B11333DC0303A17
   tcl: 22=>23 - MISC1: 0x20140514 0010 0000 0001 0100 0000 0101 0001 0100

1625 555000000000000022CC1C00CE616C47D0570F15B48C250B006AE7000B031420FA8900A00300000 0190F2F39B22D3517
   tcl: 21=>22 - MISC1: 0x2014030B 0010 0000 0001 0100 0000 0011 0000 1011

1500 555000000000000022CC1C00AD595B41C0570E14B00B450A0068C70003011420FA8900A00300000 0170E2B34A42A3116
   tcl: 20=>21 - MISC1: 0x20140103 0010 0000 0001 0100 0000 0001 0000 0011

1375 333000000000000022CC1C008C515A3DC0570D132DCB74090048C7007A0014207A8900A00200000 0150D293197282E15
tcl: 19=>20 - MISC1: 0x2014007A 0010 0000 0001 0100 0000 0000 0111 1010

1250 333000000000000022CC1C004A494937B0570C12294A94080046A700720E14207A8900A00000000 0130B252D89252A14
   tcl: 18=>19 - MISC1: 0x20140E72 0010 0000 0001 0100 0000 1110 0111 0010

1125 333000000000000022CC1C0029414831A0570C1125C9B3070046A6006A0C14206A8900A00000000 0110A21287B222614
   tcl: 17=>18 - MISC1: 0x20140C6A 0010 0000 0001 0100 0000 1100 0110 1010

1000 333000000000000022CC1C000839372B90570B102148D30600448600620A14206A8900A00000000 00F091D236D1F2213
   tcl: 16=>17 - MISC1: 0x20140A62 0010 0000 0001 0100 0000 1010 0110 0010

900 333000000000000022CC1C00E7B4362780570B0F9F072306002485005A091420DA8800A00000000 00E081A20621D2012
   tcl: 15=>16 - MISC1: 0x2014095A 0010 0000 0001 0100 0000 1001 0101 1010

600 333000000000000022CC1C00A520241A40570B0B97051204002264003A051420CA8800A00000000 00906121541151810
   tcl: 11=>12 - MISC1: 0x2014053A 0010 0000 0001 0100 0000 0101 0011 1010

400 333000000000000022CC1C006394121120570A091144B102002042002A021420AA8800A00000000 006040C0E2B10120F
   tcl: 9=>10 - MISC1: 0x2014022A 0010 0000 0001 0100 0000 0010 0010 1010

250 333000000000000022CC1C00628C110B10570A080EC3B00100204100220114209A8800A00000000 0040308091B0D0F0E
   tcl: 8=>9 - MISC1: 0x20140122 0010 0000 0001 0100 0000 0001 0010 0010

Hope it helps, boring part of the work done Cheesy

BTW, i think this bios has a 2250 strap also, once i get to 2250mhz mem it gets back to 26 mh even after copying 1750 straps to 2000