Hi and welcome to the camp, Tia A plus 2 to +0-1001 Module two.
This is less than 3.2 types of Ram. We're gonna talk about the types of Ram used and common Mother Wars.
I'm your instructor, Bill Price.
Okay, so let's look at our lesson objectives.
First, we're gonna talk about what is Ram random access memory. Then we're gonna talk about dim duel In line memory modules So dim. Small outline duel in line memory modules.
What is DRAM or D? RAM? Dynamic Ram. Random access memory. What is SD ram synchronous dynamic random access memory.
And finally, we're gonna talk about what is DDR double data rate, DDR two, DDR three and DDR four. And you may remember these from an earlier lesser, but we're gonna go into more detail,
so let's go and get started.
So, what is ram random access memory.
Think of memory or RAM as your systems. Short term data storage.
In a very early lesson, we learned that your system at its basic level outputs information that was put into it. That data or information is retreated from your hard drive storage or wherever it's stored for a long term storage and loaded into ram where you're working on it, then return once you're done with it
while that data is being processed or uses temporally stored in RAM
RAM or random access memory is the place where data resides while you're working on it, or when your program is using it. So again, we talked about briefly when you're working on a spreadsheet or a document or something like that, while it's active and you're working on it. All of that is being done in your ram when you're done with it and you save it,
that guy and you're close it up
that goes right back to your permanent storage or your long term storage, which may be your hard drive
or whatever type of our storage device that you have to store things for long term.
So the process of transferring all the data back and forth from memory happens all the time in your system. The faster your system can perform these transactions, the better the overall experience is. So when asked about how much memory does your system have? This is the Mary that is being referred to is not how large of storage or hard drive devices.
It's how much memory you have in your system.
If your system has low memory, applications will take longer to retrieve and be processed in the packing in memory. And we've all experienced that before. When you have low memory, it's a long wait while things are being processed and being retrieved.
So let's first start talking about dim the duel in line memory modules. Since these were the older models. A dim duel in line memory module is a dim is a model that contains water. Several random access memory ram chips on a small circuit board with pins that connected to the computer motherboard.
Each side of the dim has models on it that are connected together.
They are separate, though dims have a 64 bit data with which gives them became ability to transfer data from these memory modules in the 64 bit data blocks at a time.
Moving onto so dim small outline duel in line memory. Macho
standard M is in the former rectangular stick, approximately 5.5 inches and lift the small outlined duel in line memory module or the sodium is about the half the size of that. It's about 2.7 inches long. Both types of dams are most commonly at most, 1.2 inches tall.
So dims are you mainly used in portable computer devices such as laptops and tablets. So this is your smaller the modules that would be in those portable devices. So let's look at the dim small outline doula line memory modules, the sodium sze.
And, as you see, we have him laid out here and you can see the various characteristics
of these different versions. And there is one, um, characteristic that you could see straight off from looking at these is that the notches are in different places, depending on the version of the sodium. If we first look at the 200 PN the DDR 200 peons sodium module, you could see that the notch at the bottom
along the line of peons
are toward the right hand side of the module.
If we go down to the next dim, the DDR two at 240 pans the notches pretty much in the same relatively almost relatively same area down to the DDR 3 200 fan
PN rather that notches move totally over to the left inside. And finally, of the DDR 4 260 pin is back over more toward the almost on the center, but toward the right again. So this basically shows you that these memory modules are not backwards compatible.
You would not be able to take a DDR 20 PM memory module and put that into a newer,
um, mobile device that's requiring a DDR 460 pen Montreuil. The pins would not lined up the modules. We're not line up, so therefore, you would not be ableto to seat the Rams.
Okay, so what is D RAM? Dynamic random access memory
and dynamic random access memory Random means that the information in memory convicts excess any time in the memory module is in at any place.
Data's not retrieved in a sequential process, it can be retrieved randomly. Any address of data is used to get the end of the data.
The word dynamic means that memory has to be refreshed while your system is powered on and running. Thousands of refreshes happen to your D ram to retain the data that it's holding once the power is removed your system and turned off. Data is released back to memory.
So you know that shows you or you probably have that experience before. Or if you're worrying on something and the computer
randomly shuts down or turns off, that's returned back to memory in your information is lost.
So what is SD Ram synchronous dynamic random access memory?
D Ram is a synchronous. This was a problem with gathering data as it came in, so it could be cute for process that it was working with because D ram was a synchronised, it was not going to work with fast processors as technology's got faster and faster. This was a a bottleneck, more or less
trying to gather this data when it wasn't a secret in this process.
So then we came along with SD Ram or Secret ist Dein, dynamic random access memory. It's a type of D ram that is synchronized with the processor system bus for speed advantage, since diagram is synchronised and therefore relies on a clock to synchronize signals signals
creating predictable, orderly cycles and of data fetches and rights.
However, SD Ram transferred data on the edge of the clock, and we're gonna look at that a little bit further, give you further, more understanding.
So in this diagram we have the clock cycle and you could see at the top and blue. We have the SD ram and that's where it's think. The the gathering of the data on the top of the clock cycle
now D d r or SD ram DDR SD ram means that this type of SD ram fetches on both the leading and the falling edge of the clock symbol that it regulates. So that's gonna lead us into another discussion. Talking about DDR
What is DDR? DDR is the double data rate transfers of data on both the rising and the falling of the clock cycles or twice per cycle. And again, if we go back to the previous slide, you look at the SD ram.
It cycles the data just on the upside or the one side of the clock at the top.
But the DDR, it cycles it both on the up and the bottom.
So the DDR the double data rate transfers data on both the rising in the falling of the clock single single of twice per cycle,
makes higher transfer rates possible due to his efficient and strict control of data timing and clock signals. It's not backward compatible or forward compatible. DDR three will not fit in a motherboard rated for DDR two, and we have some of the transfer rates listed here. Below the DDR
transfer rate is a 60 100 militants per second
DDR to 2133 DDR 3 26 66 DDR 4 32 100
So we've covered a lot of information about Ram. We talked about what is ram random access memory we follow that went into the dim the D I m m the duel in line memory modules. Then we talked a little bit more in detail about the SOA dams. Small outlined, duel in line memory modules.
Then we had ah, discussion on the S D Rams giving the d ram the the dynamic random access memory followed by SD Ram synchronous dynamic random access memory and we fund a start off with the DDR, the double data rate, DDR two, DDR three and DDR four.
So that is it for this lesson. We're gonna be talking about ram in our future lessons. So until then, we will see you in the next lesson.