Mixing Crucial & Kingston?

[wallijonn]

Now that Crucial no longer makes or carries double sided PC3200 512MB RAM, has anyone mixed Kingston & Crucial in the same box? I'm hoping that Kingston has double sided mem in 512MB as I think they both use Micron chips and the Kingston Value ram looks to have the same timing. Does anyone know for sure? The mobo is an Intel D875PBZLK.

[CrowdAds]

[yamawho]

I mixed Crucial and Infinion ddr333 512mg sticks running dual channel in a P4P800.

Although many advise against it, it worked for me and they are running at 220 FSB

These stick were hand picked and came from systems I had running P4S533 systems that oced to 400 mhz.

If your sticks run at the same timings with SPD it might work.

[JRN]

I mixed 2 Crucial 512's (3200's) with 2 Kingston 256's (3200's) in a dual channel board (intel d865gbf). BIOS specs each chip as DDR400 and when installed individually the system memory speed specs at 400 MHz. However, when they are all installed together the system memory speed drops to 320 MHz.

I was about to submit a new post about this when I saw your's. Why does this happen?

[wallijonn]

Were you mixing single sided with double sided? Did you mix ECC and non-ECC? What were the exact part numbers involved?

I can see why you wanted 1.5G as WXP can only address about 1.5G of mem. I was tempted to go this route, also. But it may necessitate low density 512's with high density 256s to get the memory controller chip to page effeciently (which I surmise may be your problem).

a DS 512 has 16 chips on it. 512/16 = 32MB/chip.
a SS 512 has 8 chips on it. 512/8 = 64MB/chip.
a DS 256 has 16 chips on it. 256/16 = 16MB/chip.
a SS 256 has 8 chips on it. 256/8 = 32MB/chip.

So you'd probably want SS 256 (32MB/chip) with DS 512 (32 MB/chip). It would be slow, but probably not as slow as SS 512 (64 MB/chip) & DS 256.

What happens when mixing SS & DS is that the mem controller has to work twice as hard on the SS (since it cannot use an address bit to access both sides. It can only access one side of the DIMM). Instead of using 1 algorithm (which uses 4 interleaving bits, 2 upper and 2 lower) it makes up two algorithms (1 upper bit and 2 lower bit addressing).

So if you have one size in channel 0 and another size in channel 1 it will interleave differently. And if you you have DS in channel 0 and SS in channel 1 it will again interleave differently.

In your case that comes out to a 20% drop. I can only surmise that you have mixed DS and SS DIMMS.

Basically SS DIMMs force the MCH to not select one whole side of a DIMM, which means that one upper bit of the address doesn't get toggeled. It'll still toggle the lower 1 or 2 bits (bits 30, 31) though. 3 bits toggelling instead of 4 will introduce a latency. (I always say about a 25% drop).

How did you find out that you were running in DDR320? (Why not DDR333?)

http://www.anandtech.com/memory/showdoc.aspx?i=1839

ftp://download.intel.com/design/chip...s/25273001.pdf (notice that "320" on page 6?)

Notice how having just one channel populated puts you in Single channel mode. So you'd need 1 DIMM in channel A and 1 DIMM in channel B to make it go into Dual channel.

How do you have your mem configured? 512 512 256 256 or 512 256 512 256? For that matter do you have it 256 256 512 512 or 256 512 256 512? You may have to experiment a little to see which configuration gives you the best performance.

When you boot up do you see "Dynamic Paging Mode Enabled"?

I also wonder if PAT is Dual Channel Lock Step Mode (Linear).

Are you overclocking?

Do you have the CT6464Z40B.E16T or the CT6464Z40B.8T part?

If you have the CT6464Z40B.E16T (512DS), do I sell you mine or do you sell me yours? Mine is 6 months old. CT6464Z40B.8T (512SS) is easy enough to find. I want DS (.16T) only. $175?

Originally Posted by RJN

BIOS specs each chip as DDR400

Does it see each set as 3-3-3-8 by AUTO SPD?


.

[JRN]

The 2 Crucial sticks are:
512MB #CT6464Z40B/DDR/PC3200/CL=3/Non-parity/Non-ECC/Unbuffered/Double sided (16chip)

The 2 Kingston sticks are:
ValueRAM's KVR400X64C3AK2/512 is a kit of two 32M x 64-bit (256MB) DDR400 CL3
SDRAM (Synchronous DRAM) memory modules. Total kit capacity is 512MB. The
components on each module include eight 32M x 8-bit (8M x 8-bit x 4 Bank) DDR400
SDRAM in TSOP packages. Each 184-pin DIMM uses gold contact fingers and requires
+2.6V. The electrical and mechanical specifications are as follows:
FEATURES:
Clock Cycle Time (tCK) 5ns (min.) / 10ns (max.)
Row Cycle Time (tRC) 55ns (min.)
Refresh Row Cycle Time (tRFC) 70ns (min.)
Row Active Time (tRAS) 40ns (min.) / 70,000ns (max.)
Single Power Supply of +2.6V (+/- .1V)
Power (IDD0) 2.184 W (operating)
UL Rating 94 V - 0
KVR400X64C3AK2/512
512MB (256MB 32M x 64-Bit x 2 pcs.)
DDR400 CL3 184-Pin DIMM Kit

I got my information from the board BIOS. Even though the BIOS shows the mem chip information correctly it shows the "system memory speed" to be 320MHz - not 333MHz.

The opening screen shows "DDR 320->operating in dual channel mode".

I configured the memory with the Crucial 512's in the slot 0 banks and the Kingston 256's in the slot 1 banks (ie. 512/256 - 512/256).

I'm not overclocking.

For information about the board I am using (D865GBF) you need to go to:
ftp://download.intel.com/design/chip...s/25303601.pdf

The url you provide is for the 875 chipset.

I have to assume that my PAT is in "dual channel lock step mode" since that is what the Intel 865 chipset Memory Controller Hub supports (see page 7).

Originally Posted by wallijonn

Do you have the CT6464Z40B.E16T or the CT6464Z40B.8T part?

If you have the CT6464Z40B.E16T (512DS), do I sell you mine or do you sell me yours?

You'll just have to suffer!

[wallijonn]

Originally Posted by JRN

Kingston KVR400X64C3AK2/512 is a kit of two 32M x 64-bit (256MB) DIMMS. The components on each module include eight chips.

Well, there's your problem. All the DIMMs should be Double Sided. You're running in mixed mode, so it's the worse scenario. Your BIOS should show each mem stick running at 3-3-3-8 by Auto SPD.

The difference between the i865 and the i875 is that the i865 works best with two DS DIMMs and the i875 works best with four DS DIMMs. The Intel .pdfs are almost identical. Check page 13 in the i865 .pdf. Your Performance factor is 4 (Rank = sides per DIMM). So you should either go to all SS or all DS. It won't make a difference - they'll both perform the same if you have 4 DIMMs. But, it'll perform best with just TWO DIMMS.

http://www.valueram.com/datasheets/K...4C3AK2_512.pdf

You can get onto the Kingston website, search for that part number and it will list all the mobos that use that memory. Then sell them off.

You'll just have to suffer!

Try adding a smiley next time.

[JRN]

wallijonn,

Thank you for the explanation. I was in the dark as to why that was happening.

I bought the Kingston and Crucial at different times and when I built this computer I just threw it all in.

If you really need more DS ram contact Crucial. I got my sticks from them about a week ago so they must still have some in their warehouse.

Please excuse my "humor". I really do appreciate the help you've given me today and I didn't intended to offend you.

If you could use the Kingston ram let me know - I'd be glad to send it to you for free.

JRN

[wallijonn]

RJN,

Thanks for the kind offer, but I wouldn't have any need for it.

I send an email to Crucial about once a week and they keep telling me that they do not have any.

[wallijonn]

I just found out that Kingston uses Infineon chips.

I may have to look into Corsair CM64SD512-3200. Some say that it has 16 chips (32x16) (ZipZoom) and others (newegg) say that it has 8 chips (64x8). But at least this part MAY use Micron chips. One picture didn't show the "MT" on the chips. hmmm.

There's a Value Line but the CM series uses JDEC standards, so it should be more reliable.

Time to call Crucial by phone.

[3 of 7]

I don't think your going to be too happy about what I'm going to tell you here....
What CPU does this system have in it? I suspect one that runs at 533 correct? There are serious memory speed restrictions with this mobo....
from this site http://www.intel.com/design/motherbd/bf/bf_mem.htm



Supported system bus frequency and memory speed combinations


To use this type of DIMM... The processor's system bus frequency must be...
DDR400 800 MHz
DDR333(Note) 800 or 533 MHz
DDR266 800, 533, or 400 MHz



Note: When using an 800 MHz system bus frequency processor, DDR333 memory is clocked at 320 MHz. This minimizes system latencies to optimize system throughput.




*****end quote****
so, this means if you are running a FSB of 533, the 3200 sticks will only run at 333.... maybe the 320 is because of dual channel mode?

I don't think there is a work around it from what I've seen (or haven't seen is more like it)... the more I read on it, the more confused I get

[wallijonn]

3 of 7,

JRN said that he is using two 32M x 64-bit (256MB) DDR400 CL3 modules. That should be a legal configuration. My thinking, besides blaming it on mixing Single Sided and Double Sided DIMMs, is that either it is really DDR333 memory or there is a difference in SPD timings and they are interacting, in which case going into the BIOS and setting them by hand may fix his problem. I really think that the MCH is throttling down because of the SS/DS issue.

This is why I was looking at the Corsair mem and I found out that they have a Value Select line with a -C2.5 and a -C3 part number. I wouldn't want to throw in a C2.5 part and then have it mess with the Crucial RAM (which is 3-3-3-8). I have to say that the Value Select price is tempting, but I'd rather go with server grade ram, CM64SD512-3200C3. Unfortunately their documentation says that it has both 18 chips (ECC) and 16 chips. Obviously server RAM uses ECC but why can't they just say that? Their CM512SD256 says that it has 16 chips.

Time to snap off an email to Corsair, too.

[3 of 7]

Originally Posted by wallijonn

3 of 7,

JRN said that he is using two 32M x 64-bit (256MB) DDR400 CL3 modules. That should be a legal configuration. My thinking, besides blaming it on mixing Single Sided and Double Sided DIMMs, is that either it is really DDR333 memory or there is a difference in SPD timings and they are interacting, in which case going into the BIOS and setting them by hand may fix his problem. I really think that the MCH is throttling down because of the SS/DS issue.

This is why I was looking at the Corsair mem and I found out that they have a Value Select line with a -C2.5 and a -C3 part number. I wouldn't want to throw in a C2.5 part and then have it mess with the Crucial RAM (which is 3-3-3-8). I have to say that the Value Select price is tempting, but I'd rather go with server grade ram, CM64SD512-3200C3. Unfortunately their documentation says that it has both 18 chips (ECC) and 16 chips. Obviously server RAM uses ECC but why can't they just say that? Their CM512SD256 says that it has 16 chips.

Time to snap off an email to Corsair, too.

I'm still curious about what FSB the CPU is running at..... If it's 533, the fastest ANY memory will run in this board is 333.... I have pc3200 in mine with a 2.5 celery at 400 fsb and the memory will only run at 266.... intel has this tucked away in a very hard to find spot on thier website and it says nothing about it anywhere else.