| Q. | My system more than 512MB RAM. Why does Windows say I'm out of memory?
If you have more than 512MB RAM and are running Windows 95, 98, 98SE, or ME, you may not have enough cache to handle all of your memory.
Solutions to this problem can be found at Microsoft's Web site |
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| Q. | I recently upgraded my 64MB memory with another strip of 64MB memory. Why did my computer slow down after I installed more RAM?
In most cases adding additional memory should improve your computer system performance.
However, there are possible cases when additional memory actually slows down the system.
One of the most common reason for the problem is that the PC System doesn't have enough cache memory to handle the addressing for the additional memory.
If your are experiencing this problem, the only solution is to upgrade your Processor (CPU) or the motherboard, as the cache memory cannot be upgraded.
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| Q. | What is ESD ?
ESD (Electrostatic Discharge) is Static electricity . This energy is found in air surrounding us and can damage electronics components in a computer such as Harddisk drive, Floppy Disk drive , motherboard , CPU, memory modules etc.. ESD occurs when one touch an object that conduct electricity.
To protect your memory module from getting damage by ESD, always keep electronics components in AntiStatic packaging until ready to use.
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| Q. | What is CL2 & CL3 ?
CL2 parts process data a little quicker than CL3 parts in that you have to wait one less clock cycle for the initial data. However, after the first piece of data is processed, the rest of the data is processed at equal speeds. Latency only affects the initial burst of data.
Once data starts flowing, there is no effect. Bear in mind, a clock cycle for a PC100 module is 10 nanoseconds so you probably won't notice a significant performance difference.
Most systems will accept either latency part. However, there are some systems that require either CL2 or CL3 parts.
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| Q. | Will DDR SDRAM memory work on my current PC system using PC133 memory ?
The quick answer is "NO" although DDR) SDRAM is an evolution from the current PC133 SDRAM, it will not work since both the frequency,voltage and pin out are completely different.
DDR Memory actually doubles the bandwidth available to your system and runs twice as fast as regular SDRAM.
Some of the current application of DDR SDRAM chips are found in graphics cards and game consoles.
Right now only a handful of developmental motherboards from Micron, AMD, VIA and Ali will take DDR SDRAM modules.
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| Q. | What is a "Virtual Channel" or VC SDRAM Memory ?
VC SDRAM is a proprietary non standard type developed by NEC of Japan. The VC-SDRAM memory is supported by a handful of PC systems and is said to provide better performance.
The performance between VC133 is somewhere between PC133 CAS 3 and PC133 CAS 2.
PC133 is the standard adopted by the industry for 133MHz modules.
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| Q. | Can my PC-133 memory be backward compatible to my older PC system ?
Most SDRAM is backward compatible and can run at any bus speed slower than it is rated to run.
For instance, a PC133 SDRAM DIMM is capable of running at 133MHz, 100MHz, and 66MHz. There are some older motherboards that require 66MHz SDRAM and that will not accept PC100 or PC133 SDRAM, but they are the exceptions to the rule. |
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| Q. | How can I tell if my PC133 memory is a 6 layer or 4 Layer PCB board ?
| All PC100 and PC133 SDRAM DIMMs that are manufacturerd by the original manufacturer such as Micron,Samsung,NEC,Toshiba are built on 6 layer Printed Circuit Boards (PCBs), except for modules build by 3rd party manufacturer especially from Taiwan which typically are 4 layers. Physically you will not be able to tell the difference between the 4 or 6 layer just by looking at the PCB board. The best way is to visit the manufacturer website for more information or call their toll free number to find out. |
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| Q. | What is OEM Memory ?
| OEM is an acronym for "original equipment manufacturer" and OEM memory means - the memory chips and PCB boards are made by the semiconductor manufacturer themselves -and the same memory that the largest PC manufacturers worldwide such as Dell, Compaq, Apple buy for use as original equipment in their systems. |
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| Q. | Can I mix a 128MB PC100 SDRAM DIMM with a 128MB PC133 SDRAM DIMM?
Yes,you can mix PC100 and PC133 memory in the same system. The PC133 which is a faster memory will run at the slower memory's speed (in this case PC100).
However, there are some systems that will not correctly run this memory configuration. |
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| Q. | Can you mix and match parity and non-parity modules?
No. When adding new memory, you need to match what is already in your system. Parity modules have an extra chip that detects if data was correctly read or written by the memory module, depending on the type of error. However, a parity module will not correct the error.
You can determine if your system has parity by simply counting the number of black memory chips on each module.
Parity and ECC memory modules have a chip count divisible by 3.
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| Q. | My PC came with 32MB of memory. I added 32MB in the second slot. Can I add 128MB or more in the third slot ?
Different sizes of SDRAM modules can be mixed together. You do not need to fill each memory slot with the same size module, and yes, you should be able to add a 128MB module to the existing open slot on your motherboard.
Rule of thumb, the largest module should always be placed in the first slot for best performance.
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| Q. | Will adding more memory improve Web-Browsing ?
Internet browsing speed depends on several factors, including your modem connection speed, traffic on the site you're visiting, and the other components in your system.
You will probably notice the biggest improvement from additional RAM if are viewing or working with large files , such as photos and digital audio and video, or if you switch between your browser and other applications often.
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| Q. | What is Registered SDRAM ?
The term "registered" refers to how the memory module processes signals.
Registered modules contain a register that delays all information transferred to the module by one clock cycle.
This type of memory is primarily used in servers and was designed for modules with 32 or more chips on them to help ensure that data is properly handled.
While most PCs will only accept unbuffered SDRAM, there are some that accept registered SDRAM. Keep in mind that when you install registered SDRAM, all of the modules installed in your PC must be registered because unbuffered and registered modules are not interchangeable. |
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| Q. | Should I upgrade my PC memory to PC133 or PC100 ?
If your PC has a 133MHz front side bus , you will need PC133 SDRAM.
If your PC has a 100MHz FSB, you can use PC100 or PC133 SDRAM. All PCs that accept PC100 SDRAM will also accept PC133 SDRAM; however, your memory will only run as fast as the slowest "link" in your system. If you have a 100MHz FSB or any PC100 modules installed, any PC133 modules that you install will only operate at 100MHz.
PC133 SDRAM doesn't offer any immediate benefit over PC100 SDRAM if you have a 100MHz FSB. However, if you are planning to upgrade to a system with a 133MHz FSB in the future, you may be able to use the PC133 modules you purchase now in your future system.
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| Q. | I have 512MB on my system - why does it prompt "out of memory".
If you have more than 512MB RAM and are running Windows 95, 98, 98SE, or ME, you may not have enough cache to handle all of your memory.
Solutions to this problem can be found at Microsoft's Web site. |
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| Q. | Can my system cache memory be upgraded.
No - In most cases your cache cannot be easily upgraded. In order to upgrade your cache, you will probably need to upgrade your motherboard or purchase a new system.
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| Q. | Is DDR faster than SDRAM ?
Yes. DDR transfers data twice as fast as SDRAM modules. This doesn't mean your system will run twice as fast, but your memory will. And the faster memory will improve your PC's performance.
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| Q. | What is CAS Latency ?
CAS Latency (also referred to as latency) is the amount of time it takes for your memory to respond to a command.
Specifically, it is the length of time between memory receiving a command to read data, and the first piece of data being output from memory. Latency is measured in terms of clock cycles and is often noted as CL2 (two clock cycles) or CL3 (three clock cycles).
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| Q. | What does it mean when my memory chip is marked 8ns and 7.5 ns ?
8.0ns (8-nanosecond) parts are PC100 compliant and are designed for use with a 100MHz front side bus.
7.5ns parts are PC133 compliant and are designed for use with a 133MHz front side bus.
You can use PC133 modules with a 100MHz front side bus and vice versa. However, keep in mind that your memory will only be as fast as the slowest "link" in the system.
If you install PC133 modules with a 100MHz front side bus or PC100 modules with a 133MHz front side bus, your memory will only run at 100MHz.
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| Q. | Can CAS2 and CAS3 DIMM module be mixed together?
CAS2 and CAS3 parts can be mixed. BIOS settings should reflect the CAS3 setting, as the CAS2 module will run at the CAS3 setting when it is installed with a CAS3 module.
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| Q. | Can I used a PC133 SDRAM on a 200Mhz FSB system ?
| No. PC133 memory is designed for use on systems with a 133MHz front side bus or slower. If your 200MHz front side bus is on a system with an AMD Athlon processor, you probably need PC1600 or PC2100 DDR modules |
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| Q. | What is the difference between Ram and Virtual Memory?
RAM and virtual memory are two different things. Virtual memory allows you to use a portion of your hard drive as though it were RAM. Because your hard drive is up to 100 times slower than your RAM, virtual memory is much slower than RAM.
When you upgrade your RAM, you may discover that you use your virtual memory less because you will now have more memory available to complete the tasks that were previously handled by your virtual memory.
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| Q. | How do I know when its time to upgrade my system memory?
There are several signs indicating it may be time to upgrade your memory.
If you see your mouse pointer turn into an hour glass for significant periods of time, if you hear your hard drive working, or if your computer seems to work more slowly than you expect, the reason is probably insufficient memory.
When the memory is full, your system transfers data to the hard drive. This is called swapping. Since the hard drive is considerably slower than DRAM memory, your system seems slower altogether |
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| Q. | Can I install an ECC DIMM on a Non-ECC motherboard?
Most motherboards that do not have an ECC function within the BIOS are still able to use a module with ECC, but the module will run in non-ECC mode.
Keep in mind, there are some cases where the motherboard will not accept an ECC module, depending on the BIOS programming. The only sure-fire way to test this is to place the module in the motherboard and see if the BIOS will recognize the memory addition.
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| Q. | Will buffered and unbuffered DIMMs fit into the same socket?
The two different types of modules (buffered/unbuffered) are not interchangeable and even use slightly different printed circuit boards (PCBs). If you try to install the wrong type, the first notch on the bottom of the module will be offset.
You can determine if the module is buffered by looking at the leads next to the first notch. If the leads are evenly spaced, the module is buffered. If the leads are not evenly spaced (a larger PCB area next to the lead) the module is unbuffered.
Buffered EDO and FPM DIMMs have a buffer logic chip that is used to distribute the load placed on the chipset and is primarily used only in servers on PC platforms. Apple computers have used primarily buffered modules until their recent G3 and G4 series computers |
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| Q. | Can a PC1600 DDR DIMM be mixed with a PC2100 DIMM ?
If you have a system with both PC1600 and PC2100 modules in it, the system will work, but it will only run at a speed of PC1600.
A system will only run at PC2100 if all the modules in it are PC2100 and the system supports PC2100.
This is similar to mixing PC133 and P100 SDR SDRAM modules in a system.
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| Q. | What is the difference between a PC133 vs a VC133 DIMM ?
PC133 is the standard adopted by the industry for 133MHz modules. VC133 is a proprietary nonstandard type developed by NEC.
The VC133 memory is supported by only a few systems and is said to provide better performance. The performance between VC133 is somewhere between PC133 CAS 3 and PC133 CAS 2.
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| Q. | How do I know if I need parity, non-parity, or ECC memory?
The general rule of thumb in deciding what type of memory you need is to look at what's already installed in your system.
To find out if you have ECC, parity, or non-parity memory, count the number of chips on the module. Divide the total number of chips by three.
If you can evenly divide the number of chips by three, the module is ECC or parity, if not, then it is a non-parity module.
So what if your system does have ECC or parity memory (the chips are evenly divisible by three), how do you know which one you have? One way is to look at the part numbers on the chips of your module. If each chip has the same part number, you have ECC.
If one chip is different, you have parity.
If you are building a PC and deciding which type to use, the following guidelines should help. If you plan to use your system as a server or a similar mission critical type machine, it is to your advantage to use ECC. If you plan to use your PC for regular home, office, or gaming applications, you are better off with non-parity.
Using ECC decreases your PC's performance by about 2%.
Current technology DRAM is very stable and memory errors are rare, so unless you have a need for ECC, you are better served with non-parity SDRAM.
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| Q. | How many speed are there for DDR memory?
DDR SDRAM comes in two speeds: PC1600 and PC2100. Despite what these names imply, DDR is twice as fast as PC100, not roughly twenty times faster.
PC100 SDRAM modules have a bandwidth (the amount of data they can move) of 0.8GB/sec. Since DDR SDRAM can move data twice as fast as SDR SDRAM, 200MHz DDR (100MHz doubled) has the bandwidth of 1.6GB/sec, or 1600MB/sec.
Hence, the name PC1600. 266MHz DDR SDRAM (133MHz doubled) has the bandwidth of 2.1GB/sec and is referred to as PC2100.
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| Q. | What is the difference between SPD and Non-SPD DIMM?
SPD (serial presence detect) is a small non-volatile RAM chip attached to SDRAM modules that contains information about the memory.
This information includes the number of row addresses, number of column addresses, error detection/correction, refresh rates, data width, and the interface standard.
It also contains less important information such as the module serial number and manufacturer code. When your computer powers up, it sets the row and column settings and the timings for the module based on the information in the SPD.
SPD is required in SDRAM that is 66MHz, PC100 and PC133 compliant. Standards set by Intel and JEDEC ensure that data is entered in appropriate locations so the motherboard BIOS can understand what this data means.
The SPD standard allows greater flexibility for incorporating identification of new features and technologies on memory modules.
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| Q. | What is the difference between buffered and registered memory?
DDR and SDRAM can be unbuffered or registered. EDO and FPM can be buffered or unbuffered. Buffered modules contain a buffer to help the chipset cope with the large electrical load required when the system has a lot of memory. Registered modules do not have a buffer but do contain a register that delays all information transferred to the module by one clock cycle. Buffered and registered modules are typically used only in servers and other mission-critical systems where it is extremely important that the data is properly handled.
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| Q. | What is the difference between 3.3V and 5V Memory?
| Some systems require 3.3-volt modules, and others require 5-volt modules. The two are not interchangeable, and the different modules actually have slightly different notches so that you won't accidentally install a 5V part in a 3.3V slot or vice versa. |
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| Q. | How can I tell if a DIMM has 2 Clock or 4 Clocks ?
Physically looking at a memory module, there really is not a distinguishing mark to determine if the module is 2-clock SDRAM or 4-clock SDRAM.
The only way to distinguish the two parts is through the part number markings or data sheets supplied by the manufacturer |
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| Q. | What is the difference between SIMMs and DIMMs?
DIMM stands for dual inline memory module, and SIMM stands for single inline memory module. The gold or tin pins on the lower edge of the front and back of a SIMM are connected, providing a single line of communication paths between the module and the system.
The pins on a DIMM are not connected, providing two lines of communication paths between the module and the system, one in the front and one in the back.
SIMMs and DIMMs are not interchangeable; they are different sizes and they install into different types of sockets. |
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| Q. | What's the difference between EDO and SDRAM?
Extended data out (EDO) memory and synchronous dynamic random access memory (SDRAM) are two different types of memory technology. SDRAM is the newer, faster type of the two. The biggest difference between the two is that SDRAM is synchronized to the CPU clock.
Most systems accept either EDO or SDRAM, but not both.
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| Q. | My system have both SIMM and DIMM slots, can I used them all?
| Maybe. If your system has both DIMM and SIMM slots, you may be able to fill all the slots. |
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| Q. | Norton Diagnostics' memory test fail after I installed more memory, Why ?
If you have more than 256MB RAM installed, you will receive a memory failure message when you run Symantec's Norton Diagnostics. The problem is caused by a limitation of the test and does not mean that you have faulty RAM.
According to the Symantec Web site, "Norton Diagnostics cannot run a memory test on systems having more than 256MB of memory. This is a limitation of Norton Diagnostics and it is not a problem with your computer's RAM."
Symantec doesn't currently have a way to fix this problem, so your best course of action is just to ignore any error messages you receive.
You can find Symantec's description of the problem at http://service1.symantec.com/SUPPORT/nunt.nsf/docid/1999090713442709&src |
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| Q. | What is the difference between synchronous and asynchronous memory?
| Synchronous memory is tied to the speed of the front side bus while asynchronous memory is not. DDR and SDRAM are example of synchronous memory, and EDO and FPM are examples of asynchronous memory |
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| Q. | What is the Rambus and SDRAM, are they similar technology ?
RDRAM stands for Rambus dynamic random access memory. Rambus and SDRAM are two different kinds of memory technology.
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| Q. | Can you mixed ECC and Non-ECC DIMM Module ?
No. When adding new memory, you need to match what is already in your system. ECC (error checking and correcting) modules have an extra chip that detects if the data was correctly read or written by the memory module. If the data wasn't properly written, the extra chip will correct it in many cases (depending on the type of error). Non-ECC (also called non-parity) modules do not have this error-detecting feature.
You can determine if your system has ECC by simply counting the number of black memory chips on each module. ECC (and parity) memory modules have a chip count divisible by 3. Any chip count not divisible by 3 indicates a non-parity memory module.
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| Q. | Can I used 30pin SIMM and the 72pin SIMM together?
The answer to this question will vary depending on the type of system you have. In a system with a 32-bit processor (486 for example) 30-pin SIMMs must be installed in groups of four, and a 72-pin SIMM can be installed individually. In Pentium class systems, however, you cannot use 30-pin SIMMs, and 72-pin SIMMs must be installed in pairs. You can use 30-pin and 72-pin SIMMs together if the motherboard has the sockets for them.
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| Q. | Can you mixed and match EDO with Fast page mode (FPM)memory?
| No. Extended data out (EDO) and fast page mode (FPM) memory modules are not interchangeable. You need to match the memory that is currently in your system. |
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| Q. | What is the difference between SDRAM & SGRAM?
Synchronous graphics random access memory (SGRAM) is a type of DRAM that is designed for graphics hardware requiring high-speed throughput for applications such as 3-D rendering and full-motion video. SGRAM is often integrated into your motherboard or graphics card.
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| Q. | What is EEPROM ?
EEPROM stands for "electrically erasable, programmable, read-only memory." While data stored in DRAM is lost when the power is turned off, data stored in EEPROM can be retained when the power is turned off. EEPROM can also be erased and reprogrammed.
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| Q. | What is the difference between SDRAM & SRAM ?
Though the names look similar, SDRAM and SRAM are really quite different. Static random access memory (SRAM) is usually used for the cache of a system. It is very fast and very expensive, but a relatively small amount is needed to build a cache. Cache memory was designed to improve upon the performance of the processor and the memory subsystem, and is usually located next to the processor.
Most desktops and laptops use dynamic random access memory (DRAM) for the main system memory. Synchronous DRAM (SDRAM) is a particular type of DRAM used by some systems. Other types of DRAM include fast page mode (FPM), extended data out (EDO), and double data rate (DDR or DDR SDRAM). |
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| Q. | Can you mixed and match RDRAM with SDRAM?
| Unfortunately no. RDRAM (also called Rambus) is a very different technology from SDRAM, and the two are not compatible with each other |
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| Q. | Can I use PC133 or PC100 SDRAM in my PC that has a 66MHz front side bus?
All SDRAM is backward compatible and can run at any bus speed slower than it is rated to run.
For example, a PC133 SDRAM DIMM is capable of running at 133MHz, 100MHz, and 66MHz. There are a few older motherboards that require 66MHz SDRAM and that will not accept PC100 or PC133 SDRAM, but they are the exceptions to the rule.
Keep in mind that your memory run will only run as fast as the slowest component installed. If you install PC100 memory on a system with a 66MHz front side bus, the memory will only run at 66MHz.
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| Q. | What is a 2 CLK SDRAM ?
2-clock SDRAM was the first generation of SDRAM that used 2 CK, or Clock lines, to synchronize the memory chips with the motherboard.
Systems that require 2-clock SDRAM won't accept 4- clock SDRAM and vice versa |
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Memory matters
