Mixed RAM types and constant rebooting

[khildram]

Hi,

 

I went trough a lot of posts on this forum, and I did not find an answer to my question, I need some help :

 

Here is my configuration :

MB: ABIT KX7-333 (VIA KT333 Chipset, latest AwardBIOS)

CPU: Athlon XP 2200+

BIOS Settings : FSB 133MHz

Ratio FSB:AGP:PCI 4:2:1

Multiplier Factor x13

Voltage : Auto

RAM: 2x256MB of NONAME DDR PC2700 RAM.

BIOS Settings : DRAM Freq 166MHz

DRAM Clock : by SPD

Timings : CAS 2.5 - Trp 3T - Tras 6T - Trcd 3T (slowest possible for that MB)

Command drive strength: Auto

DRAM Access 3T

DRAM Queue Depth 4 level

DRAM COmmand Rate 2T command

DCCK Feedback Delay Auto

 

I decided to go for more RAM so I bought 2x512MB of CORSAIR DDR PC2700 Value Select RAM (VS1GBKIT333)

 

Since I installed those, I got W2K crashes, as well as random application crashes (firewall, antivirus, firefox, games, etc).

 

I ran memtest86+ 1.60 for several runs in different layouts (each time I left it running all night from 22:00 to 09:00).

 

1. NONAME in DIMM1&2 ; CORSAIR in DIMM3&4

=> errors in test8

2. CORSAIR in DIMM1&2 ; NONAME in DIMM3&4

=> errors in test5

3.NONAME in DIMM 1&3 ; NONAME in DIMM2&4

=> errors in test5

4. NONAME in DIMM1&2

=> no errors

5. CORSAIR in DIMM1&2

=> no errors

 

I tested mixed 1&3 + 2&4 because I I saw that thread :

 

http://www.houseofhelp.com/forums/showthread.php?t=37354

But I think that this is not a good setup as BIOS groups "Command drive strength" for DIMM1&2 / DIMM3&4

 

I also noticed that the NONAME have chips on one side of the SIMM while the CORSAIR have chips on both sides.

 

Setting DRAM Clock and DRAM Timing to "by SPD" does not help

 

My question is what can cause that problem. I do not have crashes if I use only NONAME or only CORSAIR.

I read some people in this forum talking about Dual Channel activing/deactiving; how do we do that? What is it for?

 

Thanks in advance for your help.

[khildram]

Note that my MOBO's user guides show :

 

- Four 184-pin DIMM slots support PC1600, PC2100 and PC2700 DDR/SDRAM modules

- Support 6 banks up to 3GB DRAMs for un buffered DDR/SDRAM modules (64, 128, 256, 512MB and 1GB DDR SDRAM). For PC2700 DDR SDRAM modules, it supports 4 banks up to 2GB DRAMs for unbuffered DDR/SDR modules (64, 128, 256, 512MB and 1GB DDR SDRAM).

- Support 8 banks up to 3.5GB DRAMs for un registered DDR/SDRAM modules (64, 128, 256, 512MB and 1GB DDR SDRAM). For PC2700 DDR SDRAM modules, it supports 6 banks up to 3GB DRAMs for registered DDR/SDR modules (64, 128, 256, 512MB and 1GB DDR SDRAM).

 

Does having 2 one-sided DIMMs and 2 two-sided DIMMs means I have 6 banks ? :confused: In that case, as it is all unbuffered, I think I will have to go without the NONAME RAM... :[pouts: :[pouts:

 

Manual can be found at :

http://www.abit-usa.com/products/mb/manual.php?categories=1&model=31

General MB page is :

http://www.abit-usa.com/products/mb/products.php?categories=1&model=31

[RAM GUY]

I would try and set the memory voltage to 2.7 or 2.8 Volts and you might try and set the timings manually to Cas 2.5-3-3-7 as well.

[khildram]

Ok, thanks, I'm going to try that then, but do you suggest "Cas 2.5-3-3-7" with the four DIMMs on or only for the CORSAIR?

 

And what about the fact that the mobo specs indicate :

"For PC2700 DDR SDRAM modules, it supports 4 banks up to 2GB DRAMs for unbuffered DDR/SDR modules (64, 128, 256, 512MB and 1GB DDR SDRAM)."

 

What are the banks ?

 

Thanks again for your help.

[RAM GUY]

512 Meg and larger modules are almost always double bank AKA Rank. So the 512 Meg modules from us will be double ranked. In other words if you have 2 512 meg modules that would 4 banks/ranks of memory!

[khildram]

Hello again,

 

My BIOS settings only allow 6T of 5T for Tras; so I can not set it to 7T.

 

I once found on these forums a great link (to CORSAIR site if I remember well) that show a flash animation about how RAM works and what the different timings. I think it mentionned banks.

 

Do you guy still have that link? I need to understand what banks are to determine how many they are on my mem sticks

 

Regards & thanks in advance

[RAM GUY]

Yes its called memory basics presentation, look in the top right corner of the forum. And I just told you, all 512 Meg modules would be double rank. And most 256 Meg would be single sided or rank.

[Wired]

http://www.corsairmemory.com/corsair/products/tech/memory_basics/153707/index.html

 

Top right of this very page, right under About Corsair :)

[khildram]

Ok, so that's the trick, the chipset of my mobo does only support 4 banks of PC2700, and that's why all 4 stick are recognized but does not work well...

2 x 512 CORSAIR = 4 banks

2 x 256 NONAME = 2 banks

 

BTW sorry for asking about banks twice, I did not see that you responded so fast (I posted, then tested to try 7T, rebooted and posted again) You guys are as fast as the RAM you make.

 

And thanks for the tutorial link, I knew it was that link, but I forgot that my browser version (deer park alpha) does not support flash!

 

Finally all explanations arise!

 

A BIG THANK YOU GUYS :):

[RAM GUY]

No problem, thank you for the compliment! Please let us know if you have any more questions!