Simple, simple question about Rams

Solodays

Senior member
Jun 26, 2003
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I heard that if you put a stick of DDR 2100 on a slot, and then put another stick of DDR 3500 on another slot, the 3500 will not run at full speed and it will downgrade to 2100? is this true?
 

Solodays

Senior member
Jun 26, 2003
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what if i put in 2 sticks of 3500? wouldn't that overpower 1 stick of 2100? and each of their own will run at their speed?
 

bjc112

Lifer
Dec 23, 2000
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Originally posted by: Solodays
what if i put in 2 sticks of 3500? wouldn't that overpower 1 stick of 2100? and each of their own will run at their speed?

Doesn't work like that, it all has to run in sync...

One can't Overpower the other, its just the Slowest slows the whole circuit down...
 

Solodays

Senior member
Jun 26, 2003
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even if i put in 3 sticks DDR 3500, and if theres an 2100 on board, all 4 will still run at 2100 speed?
 

DaveSimmons

Elite Member
Aug 12, 2001
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Originally posted by: Solodays
even if i put in 3 sticks DDR 3500, and if theres an 2100 on board, all 4 will still run at 2100 speed?
No, then the 3 fast sticks will band together and bludgeon the 2100 to death. After they devour its corpse they'll steal its power and run as PC4400.
 

Muck

Senior member
Feb 16, 2003
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Solodays, it all has to run in synch. Think of it as a one-lane highway with the slowest car (memory stick) always in the front.

One thing to remember when it comes to building a computer, you're only as fast as your slowest component.
 

bjc112

Lifer
Dec 23, 2000
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Originally posted by: Solodays
even if i put in 3 sticks DDR 3500, and if theres an 2100 on board, all 4 will still run at 2100 speed?

Even if you had an available 8 slots of ram, and 7 were PC 3500, all seven are going to be limited because of that slow PC 2100...

:)
 

Solodays

Senior member
Jun 26, 2003
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damn, why can't each of their own run at their speed? so..i guess chooseing the ram speed is a huge factor for future upgrade eh? thanks
 

bozo1

Diamond Member
May 21, 2001
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Boy, alot of misinformation in this thread.

What motherboard do you have? PC3200, etc., isn't going to give you squat if your motherboard doesn't support those speeds.
 

Lyfer

Diamond Member
May 28, 2003
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Rule of Thumb: They will all run at the speed of the "slowest" of the bunch.

Ex. 3xpc3200 and 1xpc1600, they all will run at PC1600 because the PC1600 is the slowest of the bunch.
 

compudog

Diamond Member
Apr 25, 2001
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All of this is true if you let BIOS run the RAM in auto. You can try and manually configure the RAM speed and timings and see if it will all run at one faster speed. Again, it will all have to be the same, bu you may be able to OC the RAM some.
 

BenjaminGun

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Jul 30, 2003
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Originally posted by: DaveSimmons
No, then the 3 fast sticks will band together and bludgeon the 2100 to death. After they devour its corpse they'll steal its power and run as PC4400.

LMAO!!
 

Solodays

Senior member
Jun 26, 2003
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Originally posted by: bozo1
Boy, alot of misinformation in this thread.

What motherboard do you have? PC3200, etc., isn't going to give you squat if your motherboard doesn't support those speeds.

nah, my mobo doesn't support 3500ddr , i'm just using it as an example.


now, what if my mobo supports maximum 2100DDR, can i put in an 3500ddr stick on it? i'm assumeing it will lower it to 2100? but will it still be compatiable with my mobo?
 

Budman

Lifer
Oct 9, 1999
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Originally posted by: bjc112
Same goes for ATA 133/100/66 as for PC 133/100

That's just not true about ATA speeds,the device will be running at it's rated speed as long as you use 80 wire ata cable.

You can have an ata 133 & ata 66 drive on the same cable & they will run at their rated speed not at the lowest.

As for pc133/pc100 ,you could oc the pc100 but if you're at 100mhz fsb they will both run at 100mhz.
 

compudog

Diamond Member
Apr 25, 2001
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Originally posted by: Solodays
what is ATA 133/100/66 ?


ATA (IDE) is an industry specification for a drive interface. The 133/100/66 are the speeds these devices can run at. Currently 133 is the latest specification and the fastest (133 MB/s burst speed) from the drive to the system.

This typically relates to hard drives and optical (ATAPI) devices.

If your drives are not SCSI, they are probably IDE/ATA.
 

AndyHui

Administrator Emeritus<br>Elite Member<br>AT FAQ M
Oct 9, 1999
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There are two factors here: the speed at which you run the RAM, and the maximum speed of which the RAM is capable of.

Each DIMM is independent. However, they all run at the speed which is set by the motherboard. If you set the motherboard to PC2100 speeds, then all the RAM will run at PC2100 speeds. If you set the board to run the RAM at PC3200 speed, then all DIMMs will run at that speed.

Of course it isn't that simple. The PCxxx ratings on a DIMM are exactly that: maximum speeds that the DIMM is guaranteed to run at. A PC2100 DIMM has been tested by the manufacturer to run at that speed, and is labelled so. There's always the possibility that the PC2100 DIMM will run at higher speeds, but the manufacturer is only willing to stand behind a PC2100 rating.

Clearly then, the speed at which you set the motherboard to run the RAM at, should be the speed of your slowest DIMM, if you decide to mix RAM. Unless you are sure that your slower DIMMs can run at a higher speed, then you should set it to the rated speed.

In your case, if you are running your board at PC2100 speeds, and you put in a PC3500 DIMM, then the PC3500 DIMM will run at PC2100 speeds.
 

thorin

Diamond Member
Oct 9, 1999
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Originally posted by: bjc112
Same goes for ATA 133/100/66 as for PC 133/100
That's incorrect. Almost all modern mothoboards/controllers support independant device timing you can run ATA33 devices and ATA66/100/133 devices on the same cable/channel no problem (assuming the use of a ATA66/100/133 cable) and they'll run at their respective speeds just fine. (The only exception is if you have a really old Optical drive running in PIO Mode).

Thorin
 

Wiseguy69

Senior member
Jun 21, 2001
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If you can afford 3 sticks of 3500, why not just get rid of the 2100 and run in high bandwidth bliss?