Here are two modifed BIOS files I am currently using. After much testing, I think it is ready to share. There are some basic mods, nothing radical, but the small tweaks have added up to improve card performance.
First, the rev4-500.rom has the default clock at 500 with a 50 Mhz delta. It is agressive, but great for water cooled cards that can handle it. The 50 MHz delta improves the vertex to shader/ROP fill rates at the higher clocks. The second file, rev4-473.rom is the same, but starts out at 473 for those cards that may not get to 500.
Second, the memory has simply been bumped to 1350 and 1300, respectively.
Third, the 3D throttle is at a whole multiple of 27 Mhz (432) and uses a 40 MHz delta versus the 35 stock. Transitions in and out of 3D are a little smoother, so that when you are close to the edge, you are less likely to experience any issues like a freeze.
Fourth, the memory timings have been tightened as such to improve memory bandwidth, but not affect OC ability. I saw around a 120 point increase on 3Dmark05 with this alone, clock for clock (results below).
All in all, this BIOS has improved my default driver settings (quality, application controlled for AA, AF) to 8900 in 3Dmark05 with my CPU at 2.5 Mhz. With a little tweaking on the driver settings (no LOD cheat), and a small OC bump to 2.65 GHz, I was able to get 9600. I am looking to exceed 10K with basic watercooling an x2 AMD CPU, but the CPU is a couple of weeks away.
It is built on the 5.70.02.11.XX BIOS build. I found it had a number of BIOS bugs resolved.
The test system:
AMD 64 3200+ @ 2.5 Ghx
BFG 7800 GTX OC@ 500 Mhz/1350 default
81.82 driver
All default drivers settings, no tweaks
Core Delta Tests, card at 1350 memory
All 3DMark05 results
Clock____0 Delta_______40 Delta_______50 Delta
490_______8347_________8570__________8593
495_______8397_________8588__________8603
500_______8451_________8728__________8772
505_______8475_________8764__________8781
510_______8534_________8769__________8823
513_______8569_________8803__________8847
520_______8577_________8805__________8864
525_______8703_________8852__________8921
527_______8710_________8912__________8980
530_______8728_________8935__________9045
535_______8765_________8983__________9078
540_______8824_________9034__________9123
Memory Speed Effect
Core at 500 Mhz plus 50 delta
Memory Clock________3DMark05_____
1200_________________8441_______
1250_________________8568_______
1300_________________8706_______
1350_________________8792_______
1400_________________8893_______
1420_________________8908_______
1440_________________8945_______
Memory Timing Change Testing results
Core at 500 Mhz plus 50 delta
________Stock___Mod
1350____8792____8985
1440____8945____9090
Here is the spec and changes on the memory:
Samsung GDDR3 1.6 Specification
K4J55323QF-GC16 / K4J55323QG-BC16
________SPEC__Change______________________________ ___________
tRC______27_____24_____Row cycle time(min) - operation (tCK)
tRFC_____34_____32_____Row cycle time(min) - Auto Refresh (tCK)
tRASmin__19_____17_____Row active minimum time (tCK)
tRP_______8______7_____Row precharge time(min) (tCK)
tRCDRD___ 9______8_____Ras to cas delay(min) for Read (tCK)
tRCDWR___5______5_____Ras to cas delay(min) for Write (tCK)
tRRD______7______6_____Row to row delay(min) (tCK)
tGR_______2____________Gapless 2 tCK
tRTW_____12___________Read to Write at same bank - CL=8tCK, tCDLR=4tCK
tRASmax__100000________Row active maximum time (tCK)
tRCDRD____9____________Ras to cas delay(min) for Read (tCK)
tRCDWR___5_____________Ras to cas delay(min) for Write (tCK)
tWR______5_____________Last data in Row precharge (7 tCK)
tCDLR_____4____________Last data in to Read delay (6 tCK)
tCDLW____0____________ Last data in to Write delay (0 tCK)
tCCD______2____________Column address to column address delay (3 tCK)
tCKmin____1.6___________Clock minimum cycle time (ns) - CL=8
tCKmax____6____________Clock maximun cycle time (ns) - CL=8
Register timings on the 7800 GTX (default is timing set 7)
0813211B
0A01060A
20270509
The new settings register values:
07112018
0A01060A
20260508
If you are curious about the history, here is the thread:
http://www.xtremesystems.org/forums/...ad.php?t=72638
BTW, I have tested the BIOS file on an eVGA GTX KO, XFX GTX EE, ASUS TOP, ASUS GTX, BFG GTX OC, and a regular eVGA GTX. All showed improvements.
The files have been fully scanned for viruses, spyware, etc then zipped.
The BIOS clocks:
Rev4-500.rom 500/1350
Rev4-473.rom 473/1300
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