Biostar TZ77XE3 + four dimms = sporadic boot failures

[Gonad the Barbarian]

Memory is 2x2Gb and 2x4Gb sets of Gskill both rated for 9-9-9-24 @ 1600Mhz @1.5V. The CPU is a i5 2500K @ 4.2Ghz. The system passes Prime95, Memtest, and gives no indication of any general stability issues. It has also never failed to resume from standby. But on every three or so cold boots or warm restarts it will fail to post with error beeps and reset the CPU and memory settings. It's been an issue ever since adding the 2x2Gb set that I'd really love to solve. Anyone run into something similar and find a fix? It's something specific to the fresh boot process, but if there's some magic fix in the Bios it I haven't found it.

 

[LTC8K6]

What is the beep code?

 

[Gonad the Barbarian]

I think it's four steady beeps but I'll have to make sure. There's a readout on the mobo I'll try to grab next time too. Last time I set all my memory timings to manual, don't know if that's made the difference yet or not.

 

[WhoBeDaPlaya]

I have the TZ77XE4 running 4x4GB of the same RAM, but have never run into this particular issue before
Only thing I can think of is maybe you're setting it to use XMP timings in the BIOS? Maybe try setting them manually.

 

[master_shake_]

are the 2 and 4gb dimms paired odd and even?

2 and 2 in 2 and 4 and 8 and 8 in 1 and 3

 

[Gonad the Barbarian]

The beep code is 3 short beeps, pause, then 3 short beeps. So, memory error? Setting all the timings to manual didn't fix it.

Here's what they're set to:

Maximum Supported Memory Clock: 666.7 MHz
Current Memory Clock: 800.1 MHz (8 : 1 ratio)
Current Timing (tCAS-tRCD-tRP-tRAS): 9.0-9-9-24
Memory Runs At: Dual-Channel

Command Rate: 1T
Read to Read Delay (tRD_RD) Different Rank: 1T
Read to Read Delay (tRD_RD) Different DIMM: 3T
Write to Write Delay (tWR_WR) Different Rank: 3T
Write to Write Delay (tWR_WR) Different DIMM: 3T
Read to Write Delay (tRD_WR) Same Rank: 3T
Read to Write Delay (tRD_WR) Different Rank: 3T
Read to Write Delay (tRD_WR) Different DIMM: 3T
Write to Read Delay (tWR_RD) Same Rank (tWTR): 6T
Write to Read Delay (tWR_RD) Different Rank: 1T
Write to Read Delay (tWR_RD) Different DIMM: 1T
Read to Precharge Delay (tRTP): 6T
Write to Precharge Delay (tWTP): 23T
Write Recovery Time (tWR): 12T
RAS# to RAS# Delay (tRRD): 5T
Refresh Cycle Time (tRFC): 128T
Four Activate Window (tFAW): 24T

The voltage shows as 1.512V, that was set to auto in the Bios, now changed to "default" to see if that makes a difference.

These are the kits:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231193
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231314

They're arranged 2-4-2-4 and sort of have to be because of the taller heatsinks on the 4GB sticks and interference of the CPU cooler over the first slot.

Edit: Also, I'm sure someone will point to it, but it will still sporadically fail with the command rate at 2T.

Edit 2: Also, all those tRD & rRW timings are auto detected from somewhere, but they're not contained in any memory profile. I feel those are suspect but can't find any info on what exactly they should be.

 

[Wall Street]

I believe the Biostar Motherboards have memtest integrated if you press a certain key on boot. Can you do a memtest and report back if it finds an error on any stick? A stick with one or two bad cells can cause intermittent errors like this.

 

[Gonad the Barbarian]

I'm not sure if it's integrated but I've run memtest off a USB stick at these settings and it passes all the tests. Heck, it even passes at 1866Mhz 10-10-10-30. :shrug: