Hi ppl.
I am experianced PC user, built my own machine (among others) and have a Q for all the hardware experts, gurus and their mentors.
Hmm.. make that ALMOST expirianced. There are alot of "unknowns" to me, especially when it comes to memory settings. The manual description is short and it, practicaly, says what I see in BIOS settings.
Specs:
ASUS A8N-Sli
AMD Athlon 64 (San Diego)
Geil Value RAM (GE1GB3200BDC) 2*512
Gainward GeForce 7800 GT Bliss (512 Mb)
SATA2 HD (Maxtor DiamondMAX 160 Gb)
Problems (hopfuly) were:
Random memory access errors in manner: "memory could not be read" and "memory could not be written" at random adresses and by random software. First time it happened was during the XP SP2 upgrade. Had to Install windows again, and SP2 upgrade went well second time. Same file, same machine, same everything.
Sad to say that I have consulted the Mobo manual when purchasing the RAM. Instead of getting Kingmax the salesman convinced me that the Gail is good choice for the mobo. And the brand I've purchased wasn't and still isn't on the ASUS vandor quality list. (doh!)
So I went poking around BIOS settings and discovered one wierd thing. Actually my DRAM configuration would differ from time to time. To be specific, if I changed "Timing mode" from "auto" to "manual" and changed, let's say, Memclock Index Value form 400 to 200 Mhz, saved the changes and restarted, then entered BIOS again, changed back the timing mode to "auto", the Memclock Index value (greyed when on auto) would show 200, 266 or 400 Mhz.
I've updated my BIOS to newest version (10.14).
Label on my memory sticks said:
DDR400 (blah, blah...) 2.5-4-4-8
BUT....
My BIOS DRAM settings were:
Timing mode [AUTO]
Memclock Index value(MHz) [400MHz]
CAS# latency (Tcl) [2.5]
Min RAS# active time (Tras) [8T]
RAS# to CAS# delay (Trcd) [4T]
Row precharge Time (Trp) [4T]
Row cycle time (Trc) [11T]
Row refresh cyc time (Trfc) [14T]
Read-to-Write time (Trwt) [4T]
Write Recovery time (Twr) [3T]
1T/2T Memory Timing [2T]
S/W DRAM Over 4G Remapping [Disabled]
H/W DRAM Over 4G Remapping [Disabled]
You can see that there are MORE settings than ones stated on the sticks.
So, I've tried to contact Geil for the complete settings list, but to no avail. Got no reply.
I've used nTune, PC probe II, CPUZ and many other tools to figure out the problem. One thing I've noticed is alot of "unknown" regarding memory installed. (brand, speed, PC probe even reported 50ns speed on the empty slot!).
I've troubleshooted the memory problem for a long time and I belive I have the solution, but I want to hear from other ppl their opinions.
Actually, I've stumbled on a info that helped me.
It is some sort of timing formula:
tras + trp = trc
trc + 4 = trfc
If that is correct, my settings were all wrong. So I've changed:
Row cycle time (Trc) [11T]
Row refresh cyc time (Trfc) [14T]
to:
Row cycle time (Trc) [12T]
Row refresh cyc time (Trfc) [16T]
That is what this post is about. I want opinions, advices and anything you guys can throw at me regarding this formula and memory settings in general.
