RAM question - 512 vs 2x256

Idz21

Senior member
Dec 22, 2001
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I'm looking for people's opinions backed up by experience and techinal knowledge on the issue.

I'm wondering if better performance can be achieved with one stick of 512 MB of RAM, or with two sticks of 256 MBs of the same brand and model. To be more specific I am referring to the Corsair CMX512-3200C2PT vs two Corsair CMX256A-3200C2PT.

  1. By performance I mean general real world speed as well as the ability to overclock.
  2. Is it easier to overclock one stick of 512 or two sticks of 256?
  3. Will I be able to achieve higher overclock speeds with the stick of 512 or two sticks of 256 of the RAM afore mentioned?

The board which this will all be happening on is the Epox 8RDA3+.

Another question I have is about the Dual Channel DDR. Model: CMX512-3200LLPT and CMX256-3200LLPT.
  1. Anyone have any experience with DDR II, and what were the results?
  2. Are the results better with DDR or DDR II?
  3. Is it easier to overclock DDR or DDR II?

If you don't think this is Highly Technical pls don't flame me. This is the only forum I saw fit for this question. I'm looking for some help before I purchase the RAM for my new system. Any help will be appreciated.


Thanks in advance.
 

Cashmoney995

Senior member
Jul 12, 2002
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Well there has been little conjecture over a set answer but here is what i can say.

If youve got Nforce 1/2/3 Motherboard then 2 sticks of 256Mb ram in slots 1 and 3 have always worked better than 512MB.
For other chipsets I havnt seen a direct corrolation or a big difference in performance.

In the olden days CPU's used to have to send data to the memory and back to have it registered within the memory. Now days it can just send it one way and receive it. (although recall is always a forward backwards thing)

Id say that there are two important things, heat transfer and price. 2 sticks transfer heat better, price is an issue you should look up.

To answer your first set of questions, whether you have a 256 stix or 512 stix ease of beggening to overclock is exactly the same. In terms of highest achievable overclocking rate, I am led to believe by several overclock posts and by some boring meaningless ram docs that I have from Samsung that a 512 stick usually uses a smaller production process on the ram, and that usually makes it a little bit harder to overclock because of size. Frequency wise, all new motherboards (within brand reason) have similar stability in keeping the frequency there but some just excel such as the Epox. The heat issue is the biggest variable, get 2 256 sticks and your heat will dissipate much faster(and even better with coolers). Oh yea...uhhh and Nforce 2 rocks with 2 sticks vs a single.

As for DDR and DDR2, correct me if im wrong guru's but you cant buy no DDR2 stick of ram for your comp within reason of cost can you? I believe that only the high end FX series of Nvidia cards use DDR2 and they cost a but load. Summary: I know nothing about the quality of DDR2 Overclockability, except that it cost a damn lot much, and that I havnt seen a stick out there yet.
 

Idz21

Senior member
Dec 22, 2001
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Hmmm interesting. I've heard that overclocking wise it would be easier to clock one stick, then clock two sticks which could have different threshholds, depending on where on the wafer they were cut from. Also I quote, "The memory bus can handle faster timings (or slower timings/higher speed) with one memory bank filled as opposed to two or three."

The part about filling the 1st and 3rd banks with two seperate 256 sticks was something I never heard. Also, wouldn't it be easier to cool one stick rather than two? I'm assuming that the 512 doesn't generate as much heat as two 256 sticks.


As to DDR II. The price difference between DDR and DDR II isn't that big. I think it differs at about a $20-50 range.
 

Idz21

Senior member
Dec 22, 2001
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Ok I heard some things that in order to take the advantage of the nForce2 chipset, it is better to get two sticks of 256 (the corsair TwinX) which are supposedly tested to work together as an identical pair. Using two sticks takes advantage of the boards dual channel capabilities providing better performance.

As of right now I'm leaning towards getting the 2x256 sticks. Anyone have any insight on this?


And to correct myself. DDR II is not the same as Dual Channel as I have previously thought. There's no boards right now that support DDR II.
 

Goatsan

Member
May 30, 2003
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i'm following with idz21's answer, i plan on getting the same board, and i'm getting 2 stick to take advantage of the dual channels, although i will have 2 512meg sticks
 

Muck

Senior member
Feb 16, 2003
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You are correct. DDR II is a very new type of RAM, whereas Dual-Channel refers to the board's dual 64-bit memory controllers.
 

Muck

Senior member
Feb 16, 2003
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When you're using an nForce board, there's nothing to debate. You're going to want to use two sticks. :)
 

Locutus4657

Senior member
Oct 9, 2001
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Due to bank interleaving having 2 sticks of ram as opposed to 1 has been faster for quite some time. So basically it's at least theoretically faster on just about all modern x86 systems. Couldn't speak for older models though.

Carlo
 

Idz21

Senior member
Dec 22, 2001
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Sounds good. Thanks for your help guys. I went ahead and purchased the TwinX Corsair 2x256 XMS Platinum Low Latency sticks for $162. Might be a little pricy, but I just went on a purchasing rampage and decided to get the best.
 

Peter

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Oct 15, 1999
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Locutus, no, sorry, the bank interleaving we have today always is toward the four INTERNAL banks that each and every SDRAM chip has. This interleaving method works even with one single-sided DIMM.
Interleaving multiple ranks (aka DIMM sides) isn't being done much, and has little effect anyway.

So there's nothing won in using more DIMMs. But there's loss a-plenty.

Firstly, the more electrical load is on the bus, the more relaxed must the timing become. This is why DDR400 and DDR333 are officially limited to two DIMMs and why DDR400 timings are so lax then; and this is also why in server environments, registered DIMMs are used that put a MUCH lower electrical load on the bus.
Secondly, more ranks means more refresh activity, which also decreases throughput.

The rules are: If you have multiple memory busses, use them. Per each independent memory bus you have, use as few RAM chips as you can. Prefer large capacity DIMMs over small ones, prefer single sided DIMMs over double sided ones.
So with a dual-RAM-channel mainboard, you want to use two DIMMs. With single channel RAM, use one single DIMM as long as you can.
 

Pudgygiant

Senior member
May 13, 2003
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What's the advantage of single-sided DIMMs over double-sided DIMMs? And why wouldn't the fact that they are single-sided make them SIMMs?
 

0roo0roo

No Lifer
Sep 21, 2002
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disadvantage is that low density mem fills up your memslots so that you'll have to toss ram to upgrade.
 

Peter

Elite Member
Oct 15, 1999
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Pudgygiant, the advantage is that you got half as many SDRAM chips on, and thus much less parasitic capacitance. The less capacitance there is, the faster can the access timing be made.
Oh, and DIMMs are called DIMMs because they replaced two original SIMMs - by being 64-bits wide instead of the SIMM's 32. SIMMs btw too could be double sided. The D is about the doubled width.

OrooOroo, when you get a DIMM that has fewer chips for the same capacity, it is a higher density, not lower.
 

LostInNet

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Aug 8, 2001
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Is size necessarily the most important factor in RAM? For example, would it be better to have two PC100 256MB sticks or a PC133 256 stick & PC133 128MB stick? I know there are other factors like CL, but I don't know how much of an impact this would have. In other words, what's the performance difference between these different types?
 

Fencer128

Platinum Member
Jun 18, 2001
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Originally posted by: LostInNet
Is size necessarily the most important factor in RAM? For example, would it be better to have two PC100 256MB sticks or a PC133 256 stick & PC133 128MB stick? I know there are other factors like CL, but I don't know how much of an impact this would have. In other words, what's the performance difference between these different types?

If you need the physical memory space (ie photoshop, etc) the size matters. If you have *enough* memory for a given application then speed is a more important consideration if you have to choose (especially if you're moving say from PC133 to PC3200 as opposed to moving from PC2700 to PC3200).

Here's what I think.

Win XP Pro works well with 512MB. If you can afford faster or more RAM than this and you're only playing games, browsing, etc. then go for fast memory. If you go for 1GB that's fine, but don't expect huge performance increases with "normal" applications.

Cheers,

Andy
 

sillious

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Jun 2, 2003
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Fencer128, you've mentioned about apps like Photoshop requiring large memory. Would rendering movie (asuming a large one) be of the same type? Photoshop deals with a lot of virtual memory, is there any idea, how much memory load, say photoshop 7, needs and what type of memory does it best utilize?


 

sillious

Member
Jun 2, 2003
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Fencer128, you've mentioned about apps like Photoshop requiring large memory. Would rendering movie (asuming a large one) be of the same type? Photoshop deals with a lot of virtual memory, is there any idea, how much memory load, say photoshop 7, needs and what type of memory does it best utilize?