Memory FAQ

  1. Do DIMM's have to be matched?
    As a general rule, a single DIMM fills the 64 bit data bus of the Pentium system. Although there are some exceptions to the rule, such as in the high-end server systems, most desktops do not require the memory modules in each slot to be matching sizes. Viking’s Online Configurator will tell you whether you must install modules in matched sizes. If no mention is made of such, the general rule will apply and you can mix the sizes in each slot or bank. The largest capacity DIMM should normally be installed in the lowest numbered slot unless otherwise stated by the system’s User’s Manual or by the system manufacturer. This is to avoid possible timing issues.
     
  2. Can I mix PC -100 and PC-133 memory in the same system
    If the system supports 100MHz memory, you can normally use 133MHz memory in it as well, and can even mix the two. However, there would be no advantage gained as the 133MHz memory will only run at the bus speed of 100MHz. Using the 133MHz memory will not make the system more stable if it is being Over-clocked. Some systems, though, will balk at the incorrect speed being reported by the Serial Presence Detect program. We suggest using only the memory specified by the system manufacturer, and cannot guarantee that memory which is different than the manufacturer specifies will be 100% compatible.

     
  3. What is PC-100 memory
    Simply put, PC100 is a faster main memory bus, transferring data at 100MHz. Up to now, the fastest common PC bus speed has been 66MHz, so PC100 represents about a 50% theoretical improvement in speed. Tests have shown a typical speed increase of over 20%.
     
  4. What does the CL2 and CL3 stand for on PC100 and PC133 memory chips?
    CL stands for CAS Latency. When a module is labeled CL2 it means there are only two clock cycles before the module can send the first block of data. CL3 means there are three cycles before the first block of data is sent. Cl2 is considered to be a small percentage faster than CL3 modules.

    PC100 and PC133 modules are manufactured as both CL2 and CL3. You will need to check with your system's requirements to see which option is compatible with your system.

     
  5. What is meant by Registered memory
    "Registered" is a means of "Buffering" the memory in SDRAM. This means that the clock signal is boosted across the entire array of memory chips so that the computer sees a clean sharp clock signal instead of a weakening clock signal as it progresses along the length of the memory path. Registered memory must be supported by the system board and cannot be mixed with "Unbuffered" modules. You must have only Registered memory to use Registered memory. This is a further means of eliminating the possibility of errors when reading the data in memory and is used when the data returned from memory is extremely critical, such as in scientific or financial calculations where the integrity of the data is CRITICAL. It also allows a module to be built using more chips, allowing for larger capacity modules to be made.
     
  6. What is ECC and how do I know if I should use it?
    ECC stands for Error Correction Code. It is similar to Parity, but more advanced. It can detect multiple errors in data returned from memory and actually correct a single error. ECC memory has 8 extra bits to support the ECC. The System board to be used must support ECC, and all of the memory in the system must be ECC for it to be actively supported. Your system board specifications will tell you whether or not you can use ECC.

     
  7. What is PC-66, PC-100, and PC-133?
    These are common Bus speeds used in today's PC's. PC-66 runs at 66 MHz, the clock speed of the bus between the CPU and the memory , or Front-Side Bus as it is called. PC-100 is a faster main memory bus, transferring data at 100MHz. Up until recently, the fastest common PC bus speed has been 66MHz, so PC-100 represents about a 50% theoretical improvement in speed. Tests have shown a typical speed increase of over 20%. PC-133 runs at the bus speed of 133MHz giving an even more pronounced increase in speed.

     
  8. What is Buffered Memory?
    Buffered memory uses a Buffer chip to boost the clock signal sent across the memory module so that the clock signal is seen as a clean, sharp signal across the entire module. It eliminates chances of memory errors in data sent or retrieved from memory. It is commonly used in larger capacity Fast Page Mode or EDO modules. Buffered modules have a different keyway in the contact edge and can only be used when the board supports Buffered modules. Unlike Registered modules, it is not interchangeable with Unbuffered modules.

     
  9. Why is it important to purchase memory designed and tested for a specific system rather than use generic memory?
    There are minute timing differences as well as small incompatibilities between systems. This is why Viking Components designs and tests its memory in specific systems. The testing of specific memory for a system is first production tested, then environment (motherboard) tested. Viking Components also manufactures "generic memory" for "White Box" systems, also known as "Clones".

     
  10. What is the difference between 2-clock and 4-clock memory?
    Two types of SDRAM modules are the 2-clock and the 4-clock module. Structurally, they are the same, but they are accessed differently. A 2-clock SDRAM module is set up so that each clock cycle accesses two chips on the module. A 4-clock SDRAM setup accesses 4 chips per clock cycle. To choose what kind to get, you must look into the motherboard's documentation. 4-clock modules are the more commonly used. The typical indication of the wrong type being used is a system giving error beeps and not booting as it cannot use the memory installed. The system will not proceed past POST (Power On Self Test). 2-clock was only used in 66 MHz systems. All PC 100 and PC 133 memory is 4-clock only.
     
  11. What is SDRAM?
    SDRAM is an acronym for Synchronous Dynamic Random Access Memory. The term "Synchronous" means that the clock cycle of the memory is exactly synchronized with the clock cycle of the bus. Every calculation and operation a PC performs is timed according to a clock ticking millions of times each second, its clock cycle or megahertz rating. If the memory clock cycle is not in sync with the bus clock cycle, system problems will occur.

     
  12. My system will not boot after installing your memory?
    Are you getting an error message on the monitor? If it states a Non-System Disk error occurred, check to make sure that you do not have a non-bootable disk in the floppy drive, or even the CD-ROM drive if your system can boot to the CD drive. If this is not the case, make sure that you did not accidentally bump into and dislodge any cables or power connectors when you were working in the case. The last step upon leaving the case should always be to ensure that every cable and power plug is fully seated. If this also does not resolve the problem, try just the new module alone in the system to determine if it is compatible with your system. If the system boots with just the new module, try shutting down and adding the other modules one by one to determine if there may be a chipset incompatibility.

     
  13. What is Rambus Memory?
    Rambus is a chip to chip interface design that is system wide, allowing 600 MHz transfer rates. It allows data transfer through a simplified bus that operates in a high frequency range. Rambus uses a low voltage signal swing with data transfer on both edges of a synchronizing clock pulse. The Intel Pentium IV CPU is designed to take full advantage of this new, extremely fast memory design.

     
  14. What is Cache Memory?
    Cache, pronounced "cash", is a high-speed memory designed to supply the processor with the most frequently requested data and instructions. The information located in the cache memory can be accessed many times faster than information in the system's main memory. The more information your system can retrieve from the cache memory, the more efficient the system will run. Level 1 (L1) cache, also referred to as Primary Cache, is normally located inside the CPU chip. Level 2 (L2) cache, also referred to as Secondary Cache, was normally located on the system board near the CPU in the past. In today's systems, both are physically located within the CPU and as a result are not upgradeable.

     
  15. What is DDR Memory?
    DDR memory, or Double Data Rate memory, is an evolutionary new memory technology that doubles the data though put to the processor, or CPU. It is an evolution of PC133 SDRAM, which leverages the existing production and environment to provide higher PC performance.
     
  16. What types of DDR memory are available?
    There are currently two types of DDR memory available. The first, PC1600 DDR provides a 1.6GB/second throughput of data. The second type, PC2100 DDR, provides a 2.1GB/second throughput of data. Currently, the AMD-760 chipset will support either the PC1600, or the PC2100 DDR modules.
     
  17. Do I need to remove the stickers that are on the chips of my new RAM DIMM?
    DO NOT remove any stickers from the modules. Removing these stickers will void the warranty. The main sticker is the bar code sticker which has the Viking serial number under the bar code. This bar code number gives us all of the information about the modules that we require for warranty replacement and information, as well as allowing us to determine which module you have and what its characteristics are. These stickers will not have any affect on performance nor will they be affected by the heat inside the system.

     
  18. What is the difference between Registered and Unbuffered DDR?
    Unbuffered DDR memory is targeted at the consumer or home computer market. These are for system boards that will only support up to 2GB total memory. Registered DDR memory is targeted at the commercial market and its server and workstation environments. Registered DDR will be used in systems that will support up to 4GB total memory. Registered modules are more expensive than Unbuffered modules. The type supported would depend upon the system. Currently, the AMD-760 chipset will support both Registered and Unbuffered DIMMs. Future chipsets may vary in what they will support. Be sure to check the documentation that came with your system to determine which type of memory it will properly support.

     
  19. Do all of your SDRAM modules use SPD?
    SPD, or Serial Presence Detect, is a program in an EEPROM chip on the modules of SDRAM (Synchronous Dynamic Random Access Memory). It tells the system’s BIOS what the specifications and settings of the memory module are. All of our SDRAM DIMMs have SPD programming. The system BIOS should therefore be set on AutoDetection for memory.

     

  20. What is VRAM?
    VRAM is an acronym for Video Random Access Memory. Video memory is DRAM (Dynamic Random Access Memory) with an on-board serial register/serial access memory. It is designed for video applications. By upgrading your system's video memory, the resolution on the computer's monitor can be increased depending upon the limits of the monitor itself. Programs that are graphics intensive will also run faster and have a smoother appearance


    Memory Info and FAQ

    Memory Info and FAQ 2