Memory Technology. Assignment 08. CSTN3005 PC Architecture III October 25, 2005 Author: Corina Roofthooft Instructor: Dave Crabbe

Transcription

1 Memory Technology Assignment 08 CSTN3005 PC Architecture III October 25, 2005 Author: Corina Roofthooft Instructor: Dave Crabbe

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3 Corina Roofthooft CSTN assignment 08 Memory Technology Introduction This assignment will help us understand the basics of memory technology. We will examine characteristics of different memory types and gain some experience in how to interpret memory specifications through online research. Lab Resources: 1. Text: Page Questions page Name two ways that a SIMM and a DIMM are alike. Name two ways they are different. Two ways that a SIMM and a DIMM are alike: - They can both use EDO - They both store DRAM Two ways that a SIMM and a DIMM are different: - SIMMs have less pins (30-pin or 72-pin) than DIMMs (168-pin or 184-pin) - SIMMs can store less memory than DIMMs per module. 2. What are the two possible number of pins on a DIMM? On a SIMM? On a RIMM? The possible number of pins on a DIMM is 168 or 184. The possible number on a SIMM is 30 or 72. On a RIMM 184 or Which is likely to be more expensive, a 512-MB DIMM or a 512-MB RIMM? Why? A RIMM is likely to be more expensive, as memory manufacturers must pay licensing fees to use the RDRAM technology. 4. How many notches are on a DDR SDRAM module? There is one notch on a DDR SDRAM module. 5. How does a memory cache speed up computer processing? By storing data or programs in SRAM for quick retrieval. The cache controller anticipates what data or programming code the CPU will need next and puts that data or code in SRAM, if that was what the CPU needed, it can get it without having to access DRAM, which would be slower.

4 6. Explain how L1 cache, L2 cache, and L3 cache differ. L1 cache is located on the CPU die itself, L2 cache is external inside the CPU housing, meaning it is not on the die. L3 cache is either on the motherboard, when there is L2 cache in the CPU housing, or inside the CPU housing farther away from the CPU than the L2 cache. 7. What types of memory can be used on a 100-MHz motherboard? SDRAM (PC100) and DDR-SDRAM (PC1600) 8. Looking at an SDRAM DIMM, how can you know for certain the voltage needed by the module? Different voltage SDRAM DIMMs have notches in slightly different places. 9. How many 30-pin SIMMs are installed in one bank for a 386 or 486. A 30-pin SIMM has 8 (or 9) bits, a 386 or 486 has 32-bit data paths (unless it is a 386SX, which is 16-bit), so 4 SIMM modules are needed to form a bank. 10. How many 72-pin SIMMS are installed in one bank? A 72-pin SIMM has 32 (or 36) bits so a) for a 386 or SIMM module forms a bank b) Pentium 2 SIMM modules are needed. 11. What are two current speeds of RIMMs? 1066MHz for the PC1066 RIMM (clock rate 533MHz) 800MHz for the PC800 RIMM (clock rate 400MHz) 12. List at least four things you can do if you receive memory errors during a memory upgrade. - Remove original memory and try the new memory by itself - Try installing the memory in different banks - Carefully clean the contacts - Check ALL the memory specs and make sure your motherboard supports this memory 13. What might be a symptom in Windows of unreliable memory on a motherboard? Windows may give a general protection fault, lock up unexpectedly, or randomly reboot. 14. List at least four things you can do if you receive memory errors during normal operation when you have not recently upgraded memory. - Run diagnostic tools for your memory. - Take the RAM out and put it back in, to make sure it was seated properly - Test each of your memory modules separately - Track recent hardware or software changes and make sure they are not causing the errors.

5 15. If your motherboard calls for 60-ns memory, can you substitute 70-ns memory? Why or why not? Using slower memory than advised may cause your system to crash or freeze. 70-ns memory is slower than 60-ns memory, therefore substituting 70-ns for 60-ns is a bad idea when the motherboard calls for 60-ns memory. 16. When buying memory, what can you look for that might indicate that the memory is remanufactured? Look for the dates on the chips, all chips of the same configuration (data, parity ) should have roughly the same date. 17. What are the two major categories of static RAM memory? L1 and L2 cache. 18. What improvements did DDR make over regular SDRAM? DDR doubled the speed of regular SDRAM because it transfers data on both clock edges. 19. When might there not be any SRAM on a motherboard? When all L1, L2 and L3 (if L3 is present) cache is in the CPU housing and on the CPU die. What is the SPD on a DIMM? Acronym and function. SPD stands for Serial Presence Detect and it is a little flash (EEPROM) chip on the memory that contains all specs of the model. The computer uses this to identify the characteristics of the memory module. DDR2 vs. DDR (resource 1) Figure 1 contains a graphic comparing DDR to DDR2 sockets, including the voltages used and the number of pins for each. Figure 1 DDR vs DDR2 Slot comparison 2. If a DDR2 uses a 200MHz clock rate, why is it called DDR2 400? It is called DDR2 400 because data is transferred on both clock edges, 2 x What does it mean to use DDR2 in 'dual-channel' mode? Dual channel mode accesses 128 bits at a time instead of 64 bit, doubling the transfer rate and doubling the memory speed. It requires two memory modules plugged into the appointed DIMM slots to enable dual channel mode.

6 4. What is the transfer rate using DDR2 533 devices in dual channel mode (megabytes per second)? 8533 MB/s (8528 MB/s?) DDR Dual-channel (resource 2) If you have an Athlon-64 running at 400MHz (real clock of 200MHz), what is the maximum data transfer rate (specify bits or bytes/sec) 3,200 MB/s What is the Maximum data transfer rate for the following RAM technologies: PC MB/s PC133 1,066 MB/s DDR400 3,200 MB/s DDR ,200 MB/s DDR ,400 MB/s How does a DDR dual-channel memory configuration differ from a single-channel configuration? A dual-channel memory configuration accesses memory 128 bits at a time, while a single-channel accesses 64 bits at a time. In a Pentium system, the ability to run in a dual-channel configurations depends on b) the chipset In the Athlon-64 processor the ability to run in a dual-channel configuration depends on a) the CPU Which Athlon-64 processors support dual-channel? Socket 939 Athlon 64 processors support dual-channel, because they have an embedded dual channel memory controller. How do the Gigabyte GA-8IPE1000 Pro 2 and the MSI 865PE Neo2 motherboard differ in how to install memory in dual-channel mode? The GA-8IPE1000 Pro 2 has different coloured slots and for dual channel configuration you install the memory modules in the slots of the same colour. For instance in figure 2, you would install them in either both purple or both red sockets. Figure 2 GA-8IPE1000 Pro 2 memory slots

7 On the 865PE Neo2 the modules are to be installed in the sockets with different colours. For instance in figure 3 you would install one module in a green slot and one in a blue slot to enable dual channel mode. Research Figure 3 865PE Neo2 memory slots Objective article comparing Dual Channel 400MHz Corsair RAM modules in single channel mode with dual channel mode on an AMD Athlon 4000+: Benchmarking done by a memory manufacturer in an Intel architecture, showing that different perspectives give different benchmarking results: Practical I found the manual for the P5GD2 motherboard on the manufacturer s website, Asus. Figure 4 shows a screen shot of the system memory page, followed by figure 5, a screen shot showing a picture of the DIMM module and 4 sockets found on the same page in the manual. Figure 4 System memory page in P5GD2 manual

8 Figure 5 Memory slots for P5GD2 Figure 6 shows the specifications of the RAM used with this motherboard, found on the same page in the manual. This motherboard uses unbuffered, non-ecc DDR2 DIMMs. QVL (qualified vendors list) Figure 6 Accepted memory types for P5GD2 Why does this list exist? This list exists to give users the possibility to find parts that are guaranteed to work with the product in question, much like the HCL. Figure 7 shows a single sided Kingston memory module supported for this board. Figure 7 QVL entry for Kingston 512MB supported memory

9 Figure 8 shows the supported Kingston memory module details on Kingston s website, with a vendor and US price for this part. Identifying memory (resource 3) Figure 8 Kingston s KVR533D2N4/512 memory module details I downloaded and installed the CPU-Z program. Figure 9 shows what the program looks like and table 1 lists the requested results I got from running the program on my personal workstation and on a main lab machine. Figure 9 CPU-Z

10 CPU Personal Workstation (Intel D850GB) Module size 256Mbytes and 128MB 512MBytes Max bandwidth PC800(400 MHz) PC3200 (200 MHz) Table 1 CPU-Z results Evaluating a system's memory configuration Main lab Workstation (Dell OptiPlex GX280) Processor name Intel Pentium 4 Intel Pentium Code name of processor Willamette Prescott Package type PGA-423 LGA775 Technology 0.18µ 0.09µ core voltage 3.056V / Core speed and multiplier MHz x MHz x15.0 FSB 99.7MHz 199.5MHz bus speed 398.8MHz 798.0MHz Cache L2 cache ratio Full core speed Full core speed frequency MHz MHz Memory Memory type RDRAM (dual) DDR2-SDRAM (dual) size 768MBytes 1024MBytes Frequency 398.8MHz 199.5MHz Cas latency / 3.0clocks SPD Is your personal computer using RAM in dual channel? Prove answer. My personal workstation is using RAM in dual channel, since it is using RDRAM and RDRAM is dual channel by design. Although 32bit RIMM modules, such as RIMM 4200, 4800, 6400 modules can be upgraded singly on dual channel systems. From running CPU-Z I could see that all 4 RAM slots are filled, 1 pair of 256MB modules and 1 pair of 128MB modules, if they were not installed in dual channel configuration, the system would not even boot, this can be deduced from the D850GB mainboard manual RDRAM Memory Configuration section, of which I included a screenshot in figure 10.

11 Figure 10 RDRAM memory configuration for D850GB Is the dell GX280 using RAM in dual-channel config? Prove answer Yes, the Dell GX280 is using RAM in dual-channel configuration. See figure 11 and 12 for proof. Figure 11 shows the manual showing dual-channel configuration, figure 12 shows a picture of the physical memory configuration. Figure 11 Dell manual memory section

12 Figure 12 DDR2 seating in Dell OptiPlex GX280 Conclusion Memory technology is ever changing, and manufacturers come up with new ways to confuse users, therefore it is important to understand the basics of the technology. If you can understand where it came from, how it got to where it is, then you will have a chance to keep up with where it is going. As final project for a course I took in 2003, I wrote a research paper on DDR2, an exciting new technology that was yet to be released to the general public. Starting at a mind-boggling 200MHz then, it has become a standard now and is up to 667MHz. Time to start writing about DDR3! I had not used or even seen the CPU-Z program before and found it to be a very useful tool.