Because the 's' (pun intended) in SRAM is different from the 
's' in SDRAM!  SRAM stands for Static RAM, a kind of memory 
cell using flip-flops and memory contents can be retained 
indefinitely as long as DC power is present.  SDRAM stands 
for Synchronous Dynamic RAM, a kind of memory cell using 
capacitors and cells have to be refreshed regularly to 
retain their contents.  There are a few transistors in a 
flip-flop, so a flip-flop occupies a lot more space than a 
capacitor on an IC.  One can pack several giga bits on a 
DRAM chip, but only several tens of mega bits of SRAM, as 
L1/L2/L3 cache memory on nowadays CPU.

My 2 cents.

Stephen Wong @ Hong Kong

On Wed, 24 Apr 2007, mtsukanov@gmail.com wrote:

> awsome. thanks for the responses.
>
> why is there such a difference in capacity between the two?
>
>

awsome. thanks for the responses.

why is there such a difference in capacity between the two?

On Sat, 14 Apr 2007 17:50:53 +1000, The Real Andy <therealandy@nospam.com> wrote:

>On 13 Apr 2007 09:03:06 -0700, mtsukanov@gmail.com wrote:
>
>>On Apr 13, 11:10 am, "Dave Hansen" <i...@hotmail.com> wrote:
>>> On Apr 13, 9:25 am, mtsuka...@gmail.com wrote:
>>>
>>> > why use one rather then the other in a certain application
>>>
>>> Same reasons as always.  Cost vs. capacity vs. complexity vs. power
>>> consumption vs. speed vs. whatever.  Choose what fits your
>>> requirements best.
>>>
>>> Regards,
>>>    -=Dave
>>
>>capacity and cost aside. Speed you can get equivalent speeds

But speeds are not entirely equivalent, as with SDRAM you have addressing and refresh overheads, so
speed for accessing completely random addresses is very much slower  than the burst rate for
consecutive data within a row. 

On 13 Apr 2007 08:10:48 -0700, "Dave Hansen" <iddw@hotmail.com> wrote:

>On Apr 13, 9:25 am, mtsuka...@gmail.com wrote:
>> why use one rather then the other in a certain application
>
>Same reasons as always.  Cost vs. capacity vs. complexity vs. power
>consumption vs. speed vs. whatever.  Choose what fits your
>requirements best.

.. and temperature range. With static RAMs the power consumption is
quite stable between -55 C .. +125 C, however, with dynamic RAMs the
high refresh rate at higher temperatures will consume quite a lot of
power, even if the memory is not accessed.

Paul

On 13 Apr 2007 09:03:06 -0700, mtsukanov@gmail.com wrote:

>On Apr 13, 11:10 am, "Dave Hansen" <i...@hotmail.com> wrote:
>> On Apr 13, 9:25 am, mtsuka...@gmail.com wrote:
>>
>> > why use one rather then the other in a certain application
>>
>> Same reasons as always.  Cost vs. capacity vs. complexity vs. power
>> consumption vs. speed vs. whatever.  Choose what fits your
>> requirements best.
>>
>> Regards,
>>    -=Dave
>
>capacity and cost aside. Speed you can get equivalent speeds

Those are the most important reasons in pretty much every design.

On Apr 13, 11:10 am, "Dave Hansen" <i...@hotmail.com> wrote:
> On Apr 13, 9:25 am, mtsuka...@gmail.com wrote:
>
> > why use one rather then the other in a certain application
>
> Same reasons as always.  Cost vs. capacity vs. complexity vs. power
> consumption vs. speed vs. whatever.  Choose what fits your
> requirements best.
>
> Regards,
>    -=Dave

capacity and cost aside. Speed you can get equivalent speeds

On Apr 13, 9:25 am, mtsuka...@gmail.com wrote:
> why use one rather then the other in a certain application

Same reasons as always.  Cost vs. capacity vs. complexity vs. power
consumption vs. speed vs. whatever.  Choose what fits your
requirements best.

Regards,
   -=Dave

why use one rather then the other in a certain application

seems a lot of applications use sdram rather then sram. What are the
pros and cons of each? The only siginifacnt difference I see is
density.