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Combining memory. Yikes?

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September 9, 2010 9:11:25 PM

So I already have one set of installed DDR2, and would like to know if there will be any problems of installing another set (different speeds, different company)

My current setup is 2x1 GB of G.SKILL PC2-5300 with a CL of 5
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

I am planning to add 2x1 GB of Crucial PC2-6400 with a CL of 6
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

I already know that the PC2-6400 will be dropped down to PC2-5300 automatically. My questions are:

Will there be any performance degradation(as compared to 2 sets of the G.SKILL)?
Will the cas latency for both become 6?
If I go into BIOS and turn on OC to 400 mhz (i can easily OC my current set of PC2-5300, so that's not a problem), will the motherboard simply have the PC2-6400 run as stock and only overclock the PC2-5300 (I may be misunderstanding how the memory bus controller works...)?
Would buying another set of the G.SKILL and having all the memory sticks match make it easier to OC?
Who will win the next Superbowl?
Are there any known problems to doing something like this? (i.e. different company, different speed)
And would it be worth it to spend a few bucks more to get the G.SKILL memory, so both dual channel sets match?

I know enough about computers to ask annoying questions like theses, but don't know enough to answer them.

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a b } Memory
September 10, 2010 12:25:52 AM

Generally, no, there shouldn't be any conflicts. However, caution is always advised, and if it can be helped, most would suggest not to mix. Mixing RAM, as you already know, forces the higher quality to operate at the lower quality, mainly because of physical limitation.

If the 5300 can operate at CL6 (which shouldn't be a problem), then you should set your BIOS to 6 (because the 6400 is rated for 6). So to answer your question "Will the cas latency for both become 6?" No, not unless you set this up in your BIOS.

Overclocking your RAM will apply your specified settings to all four DIMMs, not just the 6400 or 5300, or any combination for that matter.

Yes, purchasing another G.Skill to match what you currently have would make your OC easier. This simply due the fact that the specs are the same. This is not to say that if you were to procede as planned, you won't have an easy OC experience, but rather with consistancy in timing, you can rule out incompatible timing issues from the start.

The next Superbowl has already been won, the participating teams just haven't been announced yet.

The only problems you would have with mixing RAM are described above. Companies have never mattered, because a mobo can't discriminate by make.

In my opinion, spending a little extra to match your current would be worthwhile, but even if you didn't, Dual Channel wouldn't be affected.

Rules to Enable Dual Channel Mode
To achieve Dual Channel mode, the following conditions must be met:

Matched DIMM configuration in each channel
Same Density (128MB, 256MB, 512MB, etc.)
Matched in both Channel A and Channel B memory channels
OR

Populate symmetrical memory slots (Slot 0 or Slot 1)
Configurations that do not match the above conditions will revert to Single Channel mode.

The following conditions do not need to be met:
Same brand
Same timing specifications
Same DDR speed
Memory channel speed is determined by the slowest DIMM module populated in the system.

*This really depends on your motherboard. Some manufacturers use a color
-coded system (meaning use the same colors) and some require that you use the symmetrical approach (meaning same slot on both channels).
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a c 347 } Memory
September 10, 2010 12:39:49 AM

In general, I don't mix and match - can it be done yes - good idea no - degradation sort of {LCD "lowest common denominator" - slowest wins}. Then there's the timing issue and if you manually configure RAM then each will need to be set AND the Memory Multiplier again to the LCD.

Forgive my stupid question, but since you've list and it appears to be available - why not get a matched set?

Good Luck!

5-5-5-15 @ 1.8V 667 - G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 667 (PC2 5300)
6-?-?-?? @ 1.8V 800 Crucial 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
================
CAS 6 1.8V 667 = your timings; Your G.SKILL has better latency but worst speed; overall you'll be slower {LCD}
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September 10, 2010 2:42:48 AM

T_T said:
Generally, no, there shouldn't be any conflicts. However, caution is always advised, and if it can be helped, most would suggest not to mix. Mixing RAM, as you already know, forces the higher quality to operate at the lower quality, mainly because of physical limitation.

If the 5300 can operate at CL6 (which shouldn't be a problem), then you should set your BIOS to 6 (because the 6400 is rated for 6). So to answer your question "Will the cas latency for both become 6?" No, not unless you set this up in your BIOS.

Overclocking your RAM will apply your specified settings to all four DIMMs, not just the 6400 or 5300, or any combination for that matter.

Yes, purchasing another G.Skill to match what you currently have would make your OC easier. This simply due the fact that the specs are the same. This is not to say that if you were to procede as planned, you won't have an easy OC experience, but rather with consistancy in timing, you can rule out incompatible timing issues from the start.

The next Superbowl has already been won, the participating teams just haven't been announced yet.

The only problems you would have with mixing RAM are described above. Companies have never mattered, because a mobo can't discriminate by make.

In my opinion, spending a little extra to match your current would be worthwhile, but even if you didn't, Dual Channel wouldn't be affected.

Rules to Enable Dual Channel Mode
To achieve Dual Channel mode, the following conditions must be met:

Matched DIMM configuration in each channel
Same Density (128MB, 256MB, 512MB, etc.)
Matched in both Channel A and Channel B memory channels
OR

Populate symmetrical memory slots (Slot 0 or Slot 1)
Configurations that do not match the above conditions will revert to Single Channel mode.

The following conditions do not need to be met:
Same brand
Same timing specifications
Same DDR speed
Memory channel speed is determined by the slowest DIMM module populated in the system.

*This really depends on your motherboard. Some manufacturers use a color
-coded system (meaning use the same colors) and some require that you use the symmetrical approach (meaning same slot on both channels).


Ahh kk. Thanks. You get two free internets!

And jaquith, if you really want to know, I had already ordered the crucial one ( I would've gotten the G.SKILL one, but it was out of stock. Next day, they restocked it. ARG).
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September 11, 2010 2:12:55 AM

Best answer selected by dakeeper.
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