5x86.TXT (Last Update December 5, 1995) This Frequently Asked Questions (FAQ) document is intended to assist with common customer questions on the AMD Am5x86-133 32-bit CPU. /**************************\ ** Am5x86-133 INFORMATION ** \**************************/ 1. Where can I get an electronic copy of this information? If desired, you can download a copy of this message from our BBS at 408-749-4659 (5x86.txt in PCD conference 6). There is additional information located on the AMD World Wide WEB at http://www.amd.com. 2. Exactly what is the Am5x86-133 and what is the ordering part number? The Am5x86-133 is the latest 32-bit CPU available from Advanced Micro Devices. This is an SL Enhanced CPU with a 16KB internal cache that supports write back and write through cache policies. The pin-out of the Am5x86-133 is the same as the AMD Am486DX4 Enhanced (SV8B family) of CPUs. The exact ordering part numbers for the Am5x86-133 are listed below: AMD-X5-133ADW (168-pin PGA package, 3.45 volt, 55C case temp.) AMD-X5-133ADY (168-pin PGA package, 3.45 volt, 75C case temp.) 3. I am having problems with my motherboard jumper settings. Can AMD help to determine the best settings? We cannot answer motherboard specific questions, such as how to set jumpers or configure your CMOS setup. You need to contact the motherboard manufacturer or consult your motherboard manual. 386 motherboards do not support 486 CPUs and will require a new motherboard. 4. Where can I find out whose motherboards support the Am5x86-133? For a listing of motherboard manufacturers, call our FaxBack or Literature Dept. at 800-222-9323 and get PID #19722. Listings of motherboards compatible with the Am5x86-133 will be included in this document and will also be placed on the World Wide Web in the microprocessor section on the 3 volt Motherboard Listing page as the various motherboards are tested. There should be a number of compatible motherboards listed by the end of November or beginning of December. Until that time you will need to contact your motherboard vendor about compatibility with the Am5x86-133. 5. How can I tell if my motherboard supports the Am5x86-133? If your motherboard supports the AMD Enhanced line of 486 CPUs (the SV8B family) it will PHYSICALLY support our Am5x86-133. The BIOS may have to be upgraded to run the Am5x86-133 in clock x4 mode since the CPU ID changes in this mode. However the BIOS on motherboards that properly support our Enhanced CPUs should be fully compatible with the Am5x86-133 running in clock x3 mode since the CPU ID is the same as the Enhanced 486 CPUs. In this case the Am5x86-133 could be run as a DX4-100 or DX4-120 and get the benefit of the 16KB internal write back cache even if the BIOS will not support the device in clock x4 mode. 6. What is the external bus speed for the Am5x86-133? The external bus speed is 33MHz. The Am5x86-133 CPU multiplies the input clock by 4! The CLKMUL pin on the older 486 Enhanced CPUs was high for x3 mode and low for x2 operation. On the Am5x86-133 it is still high for x3 mode and should be jumpered low for the x4 mode of operation. 7. After I installed the AMD CPU I seem to have some problems. Do you have any suggestions? If you are having problems running HIMEM.SYS or DOS4GW.EXE check your motherboard CPU voltage and type settings. Running a 3.45 volt CPU at the wrong voltage or setting up the motherboard CPU configuration jumpers incorrectly can cause these types of problems to occur. 8. My CPU seems to run fine but the BIOS reports a different type. Why? If your BIOS reports your Am5x86-133 as a different type of CPU, you may have a BIOS error or jumpers on the motherboard may not be set correctly. To update an old BIOS you will need to get an update from the motherboard or BIOS vendor. 9. Does AMD have warranty coverage for my CPU? If you have a damaged processor, it MUST be returned to the vendor from whom you purchased it. We cannot help you here in technical support. AMD does not warranty parts to the end user. The warranty coverage for your part is provided by the vendor you purchased it from. 10. My system seems to run for a while and then fails. Any ideas? If the board runs properly for some period of time and then seems to fail you may have a thermal problem. The Am5x86-133 requires a heat sink and fan. You will need to apply a thin layer of heat sink paste to assure proper heat transfer from the CPU to the heat sink. If you have intermittent problems check that the ISA bus clock is near 8MHz. The divider is in the Advanced CMOS setup. For bus speeds of 33MHz select clock/4 and for bus speeds of 40MHz select clock/5. Some green motherboards may try to slow down the processor. It may be necessary to disable power management on Green PC motherboards to eliminate intermittent problems if the motherboard does not properly support the SL Enhanced power management features. The Am5x86-133 CPU does support the industry standard 2-pin SMM mode. 11. I seem to have problems with my VL cards. Is this a CPU problem? No. You should be sure that the motherboard is jumpered for VL bus clock <=33MHz. If you still have problems you should try inserting / removing each of the Local Bus cards on your motherboard until the system works. You may need to contact the failing adapter card manufacturer to see if VL bus wait states are required for their card. 12. Some of my programs work with the older CPUs but fail with my new one. What could cause this to occur? Some older benchmarks and diagnostic software do not work correctly with the faster processors. If you are having problems running specific programs you may need to contact the respective software company to determine if there is an updated version of their software available. The AMD 80486 microprocessors are fully software compatible with programs written for the x86 microprocessors. 13. I would also like to know the cost and where I might purchase one, if not directly from AMD. AMD does not sell direct. We sell our CPUs through local distribution companies which include Anthem Electronics, Arrow/Schweber Electronics, Hamilton Hallmark Electronics, Wyle Labs and Zeus Components, Inc. You will need to contact your local distributor directly to check on price, availability and length of warranty of the product you are interested in. AMD devices are also sold through the following resellers. You should check to verify their pricing and the warranty that they provide with the devices they sell. Globelle 1-800-745-7000 JM Computers 1-800-331-2128 Liuski 1-800-454-8754 PC Wholesale 1-800-723-2257 Professional Tech. 1-800-949-5018 Riodan & Ross 1-800-727-6282 SED 1-800-444-8962 Solar 1-800-669-9568 Solomon 1-800-882-9788 14. Will there be a Write-through version of the processor? AMD has no plans to create a write through only device at this time. The Am5x86-133 internal L1 cache will fully support either the write through or write back cache policy. 15. What would the speed comparison be if the processor was placed in a computer not supporting write-back caching? The performance for the CPU would be about 8% lower if the internal L1 cache is operated in write through only policy. At the system level this would probably result in a 2% to 4% overall performance impact. 16. What are the benchmark numbers for the Am5x86-133 CPU? The benchmarks for the Am5x86-133 CPU are listed below and there is more information available on the AMD World Wide Web home page: Am5x86-133 Winstone '95 (Units) 133.0 WinBench '96 CPUMark16 155.0 WinBench '96 CPUMark32 161.0 System Configuration - Gigabyte GA486AM Motherboard - 256KB L2 cache (15nS) - 16MB DRAM (70nS) - Diamond Stealth 2 MB VRAM video card 17. Which motherboards will support the Am5x86-133 when it is released? MANUFACTURER MODEL BIOS U.S. Contact Atrend 1415 Award v3.20 (10-24-95) Abit PB4 Award v4.5 (11-06-95) Biostar 8433UUD Award 818-443-4023 UUD951102 Gigabyte GA486AM Award 818-854-9338 Holco 433 AMI 408-945-1480 (Shuttle Computer) FIC and Chicony should be bringing out motherboards in the first quarter of 1996 that support the Am5x86-133.