Which type of RAM is better?

Nigel H-J · Post by **Nigel H-J** » 30 May 2007, 12:47

I have a P4 AGP (4X) mainboard (100MHz)

On the user manual written at the front
EP-4SDA
EP-4SDA+
SIS 645 Chipset (Whatever that all means to a non Techie).

I am looking to upgrading my RAM as presently have 512.

the handbook states it supports PC1600/2100/PC2700 DDR Memory.

Having had a look (PC World) for a quick guide on prices have noticed there is quite a variation on these price-wise, why is that?

Can any-one please advise which type of DDR Memory that would be best though have to keep the cost down and also whether it may be best to just add 1Gb of RAM to the existing 512 (only have three RAM slots in total) or get another two 512's to add to the existing one.

Finally, what is the difference between the PC1600/2100/PC2700? Is one type better than the other?

I know....questions....questions and more of them!!

Late Edit: just had a look on the Overclockers site and they do not have any below a PC3200 I take it this type would not be compatible?

Many thanks

Regards Nigel.

Sl4yer · Post by **Sl4yer** » 30 May 2007, 13:31

Nigel,

PC3200 (DDR400) is compatible, and probably cheapest due to supply levels. It will just run slower in your board.

The numbers (2100, 2700, 3200) refer to the amount of data the memory can pass per second (in MB) at the rated speed. (The speed is the number used in the other naming scheme, e.g.DDR400 runs at 400 MHz, DDR333 runs at 333MHz).

The board doesn't appear to have any dual channel memory feature, so you don't need to match up any of the slots.

Have a look at Crucial - normally pretty good on price, and next day delivery:

http://www.crucial.com/uk/store/listpar ... =EP%2D4SDA

James

Charlie Bravo · Post by **Charlie Bravo** » 30 May 2007, 13:33

DDR memory is being replaced with DDR2 and soon DDR3.
Memory prices have dropped quite considerably over the past few months but as with all older hardware the prices have remained stagnant (or at least are higher than the DDR2 range.)

The different numbers you see (1600/2100/2700/3200) are the speed at which the RAM operates.
1600 = 200Mhz
2100 = 266Mhz
2700 = 333Mhz
3200 = 400Mhz

Grab yourself a stick of PC3200. Even though your motherboard doesn't support that speed, it will slow down from 400Mhz to 333Mhz and will function normally.

Nigel H-J · Post by **Nigel H-J** » 30 May 2007, 14:02

Thanks guys, that has made it a lot easier for me to understand.

Regards Nigel.

ianhind · Post by **ianhind** » 30 May 2007, 18:08

I use http://www.crucial.com/uk to see what I need.

For that motherboard:

http://www.crucial.com/uk/store/listpar ... %2D4SDA%2B

Looks like it depends what is in there already as to whether you can add or have to replace. :sad:

I suspect given the age of the motherboard it is probably 2 x 256Mb.

Edit: have just seen from you first post that it is 1 x512Mb. So if that is PC2700, you can only add one more.

Nigel H-J · Post by **Nigel H-J** » 31 May 2007, 13:45

Many thanks for the advice Ian, all sorted now.

Regards Nigel.

Post by **DaveB** » 02 Jun 2007, 15:30

To keep this little ball rolling a bit longer.. I went onto Crucial (I usually use them anyway) with a view to trying to boost my XP3200 system a little. I plonked in the mobo (Asus A7N8E-E Deluxe) and hit the 'go' button and it came back offering 3 x 1gb PC2700 dimms (only I didn't realise it was PC2700 at the time) :roll: I also tried the system checker and it correctly identified the mobo and memory and offered the PC2700 code as the best upgrade. I duly added to basket and the package arrived this morning.

Opening the box, I found 3 x 1gb PC2700 dimms so I checked the code on the dimms to the invoice then went back online and ran the test again. Low and behold, it offers PC2700. Does anyone know why it didn't suggest DDR400?? The mobo accepts DDR400 and the XP3200 is 400mhz FSB so surely an upgrade to DDR400 should have been the way to go??

I've since run the test on this pc which is an Asus A7N8X and currently has 1gb DDR400 and again, the Crucial site has suggested 3 x 1gb PC2700 and not DDR400 :roll: OK.. the chip in this pc is an XP2400 (333mhz FSB) but I gotta say it doesn't make a great deal of sense to me :think: Neither test suggested matched pairs (both mobo's can - and have - run dual channel) so what does all this say?? Is dual channel a waste of time and is 3gb PC2700 better than 3gb DDR400/PC3200

ATB

DaveB :tab:

ianhind · Post by **ianhind** » 02 Jun 2007, 19:19

Dave,

I vaguely recall previous discussions on here that in a motherboard with 3 RAM slots, if you fill all 3 of them there is a reduction in speed.

Two slots are not affected so perhaps if you had just ordered 2 RAM sticks, the PC3200 would have been recommended.

Might be worth seeing what happens on the Crucial site if you ask for 2? But perhaps the beer and sun have gone to my head :madhead:

Ian

Post by **DaveB** » 02 Jun 2007, 20:57

Hiya Ian,

There may be more to that than you realise. My flying pc (asus A7N8X-e Deluxe) has 3 slots like this one. I originally had 2x512 DDR400/PC3200 in there 'dual channel' and it ran okey doh. In an attempt to keep the speed of this old dog as high as I could, I took out the 2x512PC2700 + 1x256mbPC2700 and put them in the flying pc and now the 2x512PC3200 reside in here. Point is, the flying pc is registering the full 1.28gig but reports the memory speed at 166mhz.. not 333mhz so it may be slowed down by the 256mb dimm.

As I understand it, for dual channel to be configured correctly AND have all 3 slots occupied.. the 2 dual channel slots should have memory totalling the same as the single slot so I should, in effect, have 2x512 + 1x1gig which I don't have. Odd but this pc isn't dual channelling on the 2x512DDR400's even though it runs ok :think:

I have already emailed Crucial to ask WTF is going on so if their reply is anything like what you've suggested.. then I'll pop the 3x1gig dimms in and see what happens. However, it doesn't seem that dual channel has been considered. I didn't ask for 2 or 3 dimms btw.. I hit the button and took the recommended upgrade for that system.. which happened to be 3 x 1gig PC2700. Pity I didn't think about this at the time (or wear my reading specs) :roll: I trusted the Crucial system checker to do the right thing and now, I'm really not sure it has :think:

Odd too that checking both systems.. the increase in performance suggested by that little performance bar showed the XP3200 with 1.28gig PC2700 showed it to be about 4 marks off the max. On this system .. XP2400 and 1gigDDR400, the performance indicator showed it to be about half way along the line

I'm presuming (dangerous at the best of times) that the shortfall in performance on this system is due to it only having a 2400 CPU.. the faster ram making not one jot of difference. I'm not about to take out the DDR400 and throw the slower ram back in just to check it either

ATB

DaveB :tab:

ianhind · Post by **ianhind** » 02 Jun 2007, 21:15

Dave

I've been making a point of upgrading my sad systems to Intel 865 (yes 865 NOT 965) chipsets so that I have 4 slots, and so dual channel is easy to work out.

This 3 slot malarkey is perhaps a marketing ploy! Dual channel with 3 slots filled :think:

And in response to Nigel's first question, note that Crucial warn that his motherboard will essentially slow down if all 3 slots are filled.

Ian