DDR RAM (some q's about)

[Steve]

i was told Win 98 only recognises 700 and something MB's pf ram.

is this true? and if it is would it recognise the forementioned amount of ddr ram as it is double density?


what does the ECC in ECC DDR ram mean. i read it was only used in servers mainly and my mobo doesnt support it ( can use it but disables ECC ).

ty

[Necromancer]

Yes, win 98 only supports 798 MB of RAM, and yes, it should support DDR RAM of equivalent numerical value, as it is still only 798 MB of memory. The difference is not its double density, it is twice the speed. That's why it's called Double Data Rate RAM.

Not sure what ECC stands for, but can find it . . . however, it can only be used in servers or brand new motherboards that can interpret the data transfer format.

[Steve]

goos stuff m8, thanks buddy

[Necromancer]

Here we are, Stevie. I found just what you were looking for -- the meaning of ECC:

What is ECC memory? ECC- (Error Correction Code) is used primarily in high-end PCs and file servers and costs a little more than standard RAM. The important difference between ECC and parity is that ECC is capable of detecting and correcting 1-bit errors. With ECC, 1-bit error correction usually takes place without the user even knowing an error has occurred. Depending on the type of the memory controller your computer uses, ECC can also detect rare 2-,3- or 4-bit memory errors. However, while ECC can detect these multiple-bit errors, it can only correct single-bit errors. In the case of a multiple-bit error, the ECC circuit reports a parity error. Using a special algorithm (mathematical sequence) and working in conjunction with the memory controller, the ECC circuit appends ECC bits to the data bits and together they are stored in memory. When data is requested from memory, the memory controller decodes the ECC bits and determines if one or more of the data bits are corrupted. If there's a single-bit error, the ECC circuit corrects the bit. As mentioned, in the case of a multiple-bit error, the ECC circuit reports a parity error. Because the ECC functions occur in addition to the standard functions that the RAM in your system needs to accomplish, it stands to reason that computers with ECC are a little bit slower than non-ECC computers, so get ECC RAM because you need the additional assurance of a more stable computer system such as for a file server that needs to run non-stop for months at a time.

Information courtesy of PCs For Everyone, Cambrige, MA, USA.

Now if this isn't enough, I don't know what is!

[zza1pqx]

DDR
Double Density Random Access Memory.

Old style RAM calculates its function as each micro transitor is charged.

DD RAM calculates its function as each micro transistor is charged and de-charged. Hence twice the speed.

[Necromancer]

OK, my mistake. Guess the guy who told me it was called double data rate didn't know what he was talking about. Man, good techs here in Prince George are hard to come by!

[zza1pqx]

It might well be caled Double Data Rate......

I am from the days where 5 1/4 inch double density floppies were the thing....

However, thats how they work apparantley

[Necromancer]

No, you're right, it is double density RAM. I don't listen much to techs here in my town, since I have been able to find out more about my comp's hardware without them. And when they tell me how to diagnose a problem, they're usually wrong. Something tells me these guys here where I live are just wannabes.

[Gen. Jann *PR*]

ddr= double data rate................. but i am not an expert.......