DDR Mixing Question

[dwalden]

Ok, in my new system, I'm going to have 2 1GB sticks of PC3200 DDR RAM.

My question is, I also have 2 256 MB sticks of PC4000 DDR. Shoud I or can I also throw in the additional 512MB, or does it not work because it's a different speed?

 

[Mex]

I don't see any reason why it shouldn't work...the PC4000 DDR will just run at DDR400 along with the rest of the RAM. But, I thought there was an issue with filling all the RAM slots on AMD motherboards - the RAM would run at DDR333 and the command rate would be set to 2T, or something like that. You should make sure that issue has been resolved or it could lead to a performance hit.

 

[casewhite]

It gets alot more complicated than that. It depends on the chips winbond, samsung , crucial , hynix infenion so forth. There are about six different variations of winbond. Only bh-5 and 6 allow you to mix(UTT BH-5 will mix with standard BH-5). . You cannot mix the CH line with the BH line. On samsung only TCC5 and TCCD are compatible. On the rest of them don't even think about it. You are just about guaranteed to have stabllity problems. you also cannot cross brand lines easily. For example OCZ UTT BH-5 does not mix with Mushkin UTTBH-5. Call the manufacturer and ask. The good ones like Mushkin and OCZ and Gskill will know.

 

[casewhite]

Quick look and tech power up shows that the corsair rev 1.1 is hynix d43 and rev 3.1 is samsung TCCC. Neither are renown for stablity so you are asking for trouble.

 

[Crashman]

What are you talking about, a single unmatched pair? Of course your your matched pair has to be...matched. But the second matched pair doesn't have to be the same as the first matched pair. You can run a matched pair of Samsung PC3200 in slots 1 and 3, and a matched pair of Winbond PC4000 in slots 2 and 4, and still make it work at PC3200.

At least you can with most Intel chipsets. AMD's ODMC might require you to drop them to PC2700 speed.

 

[1Tanker]

What are you talking about, a single unmatched pair? Of course your your matched pair has to be...matched. But the second matched pair doesn't have to be the same as the first matched pair. You can run a matched pair of Samsung PC3200 in slots 1 and 3, and a matched pair of Winbond PC4000 in slots 2 and 4, and still make it work at PC3200.

At least you can with most Intel chipsets. AMD's ODMC might require you to drop them to PC2700 speed.

I don't see the advantage of adding the extra 512MB anyways, as 2GB should cover most needs. You start getting near 3GB and windows can get finnicky.

PS. Also the problems associated with AMDs IMC and filling the 4 slots really does away with any advantages to the extra memory. GL

 

[sunangel]

The reason 4 sticks of 400MHz ram run at 333MHz is because they are double sided sticks. If you use single sided sticks all four lanes will run at 400MHz. So, its perfectly okay to mix your PC4000 with PC3200.

But, I'm confused. You tag already says you have 1GB memory (2x512MB). It appears those are double sided sticks. Adding 2 more stick of 256MB each is going to cause you to drop back to PC2700 speed. Its okay to run your 2x512MB stick at whatever speed rating there at, but once you add the other, BOOM, 333MHz.

I don't know the technical reason for this, but Nvidia motherboard manuals clearly state this. So, to make a long story short...with AMD based motherboards, 1GB is sufficient if your going to run four slots of memory. Otherwise, the fall back in speed to PC2700 is greater than the benefits of the integrated memory controller on the Athlon64 chips. Your performance will actually receed instead of improving after adding the additional memory.

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[sp6yd6er6]

True story.

I run 2 gb of ram (2x512 OCZ Platinum, 2x512 Corsair XMS Pro w/ blinky lights). When I run either set by themselves, in matched pair, they run at 400Mhz, but all together at 333Mhz. To override this, you need to force a memory lock at 400Mhz in your BIOS, if your mobo lets you. Otherwise you could Overclock the FSB, whilst lowering your CPU multiplier... only if stability concerns you lol :twisted:

 

[Crashman]

I like the blinky lights, I sometimes use them to diagnose boot failures.

 

[sp6yd6er6]

Hahaha... me too. Easy to tell if the system has locked up, instantly.

 

[casewhite]

What are you talking about, a single unmatched pair? Of course your your matched pair has to be...matched. But the second matched pair doesn't have to be the same as the first matched pair. You can run a matched pair of Samsung PC3200 in slots 1 and 3, and a matched pair of Winbond PC4000 in slots 2 and 4, and still make it work at PC3200.

At least you can with most Intel chipsets. AMD's ODMC might require you to drop them to PC2700 speed.

The Intel chipsets are different. With the structure of HTT you can't mix and match with top quality memory(2-2-2-5). . It won't even boot. I have tried matched pairs of Mushkin 990992 UTT BH-5 with OCZ4001024ELDCGE-K again UTT BH-5. HTT won't boot because the EEPROMS are different. If you match other brands of modules they won't boot either unless you are really sloppy on timings(3-4-3-8) and latencies and then you have defeated your purpose. You are as the manual above says going backwards on performance. But if you are overclocking then you will be using memory dividers and you can go up to 250mhz without worrying about using the dividers and still run 2-2-2-5 on fully matched pairs.

 

[dwalden]

But, I'm confused. You tag already says you have 1GB memory (2x512MB). It appears those are double sided sticks. Adding 2 more stick of 256MB each is going to cause you to drop back to PC2700 speed. Its okay to run your 2x512MB stick at whatever speed rating there at, but once you add the other, BOOM, 333MHz.

Actually, I just bought the new Corsair 2GB PC3200. I hadn't changed the sig yet.

Essentially, I was wondering about a matched pair of Corsair 1GB chips in slots 1 and 3 and then another matched pair of Corsair 256MB PC4000 chips in slots 2 and 4

I guess I can just try and play around with it to be sure. I know 2GB should be plenty, but I figured since I have it, why not go 2.5 GB.