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AMD Duron processors manufactured according to 0.18-micrometer technology have similar architecture to Athlon processors based on the same core, with the same operating frequencies of the EV6 bus. However, because of a smaller amount of the L2 cache memory, Duron processors are less powerful than their prototypes.
Duron manufactured according to the Socket A form factor has a fixed multiplier, which can be changed only by using specialized hardware and software. Not all motherboards support these functions. Therefore, Duron typically is overclocked by increasing the processor-bus frequency.
Features of the EV6 processor bus and motherboard architecture sometimes prevent large increases in clock frequency, even though Duron has significant technological reserve.
The results of analyzing Duron operation in overclocked modes are provided in the following sections.
Processor — AMD Duron 650 (128 KB L1 cache, 64 KB L2 cache, full CPU core frequency operation, standard FSB frequency of 100 MHz, 1.5 V core supply, Socket A)
Motherboard — Gigabyte GA-7ZM (VIA Apollo KT133 chipset)
RAM — 128 MB, DIMM, PC133, SDRAM
Hard disk — IBM DJNA 372200
Video adapter — Creative 3DBlaster Annihilator Pro
Sound card — Creative Sound Blaster Live!
Operating system — Windows 98
During overclocking, the system-bus frequency was increased from 100 MHz to 110 MHz. A further increase of the bus frequency resulted in system instability, which, presumably, was related to features of the EV6 processor bus and VIA Apollo KT133 chipset, used as the basis of the motherboard in these experiments.
Test results are provided in Table 18.31 and in Figs. 18.65 and 18.66.
Figure 18.65: Duron 650 test results (CPUmark 99)
Figure 18.66: Duron 650 test results (FPU WinMark)
FSB frequency (MHz) | CPU frequency (MHz) | CPUmark 99 rating | FPU WinMark rating |
---|---|---|---|
100 | 650 = 100 × 6.5 | 55 | 3,520 |
105 | 683 = 105 × 6.5 | 58 | 3,695 |
110 | 715 = 110 × 6.5 | 61 | 3,870 |
Processor — AMD Duron 600 (128 KB L1 cache, 64 KB on-die L2 cache, core frequency operation, standard FSB EV6 frequency of 100 MHz and a data-transfer rate of 200 MHz, 1.5 V core supply, Socket A with 462 pins)
Motherboard 1 — Abit KT7 (VIA Apollo KT133, VT8363+VT82C686A chipset)
Motherboard 2 — Soltek SL-75KV+ (VIA Apollo KT133, VT8363 +VT82C686A chipset)
RAM — 128 MB, SDRAM, PC100
Hard disk — IBM DPTA-372050 (20 GB, 2 MB cache memory, Ultra DMA/66)
Video adapter — Asus AGP-V3800 TV (TNT2 video chipset, 32 MB video memory)
Sound card — Creative Sound Blaster Live!
Power supply unit — 250 W
Operating system — Windows 98 Second Edition
Tests were conducted using CPUmark 99 and FPU WinMark from the WinBench 99 package.
Figure 18.67: Duron 600 processor
The motherboards that were investigated are shown in Figs. 18.68 and 18.69.
Figure 18.68: Soltek SL-75KV+ motherboard
Figure 18.69: Abit KT7 motherboard
Supported processors — AMD Athlon (Thunderbird) and AMD Duron (Socket A processor slot with 462 pins, standard FSB frequency of 100 MHz)
Overclocking — 100/103/105/110/112/115/120/124/133.3/140/150 MHz via Dual In-line Package (DIP) switches, 100/103/105/112/115/120/124 MHz via BIOS Setup
Core voltage — 1.5 V-1.85 V, with an increment of 0.25 V
Multiplier setup — DIP switches
Chipset — VIA Apollo KT133 (VT8363+VT82C686A)
RAM — Up to 768 MB in three DIMM modules (168 pin, 3.3 V), 100/133 MHz frequency
BIOS — Award Plug-and-Play BIOS
Supported processors — AMD Athlon (Thunderbird) and AMD Duron (Socket A processor slot with 462 pins, standard FSB frequency of 100 MHz)
Overclocking — 100/101/103/105/107/110/112/115/117/120/122/124/127/133/136/140/145/150/155 MHz via BIOS Setup
Core voltage — 1.1 V-1.85 V, with an increment of 0.25 V
Multiplier setup — BIOS Setup
Chipset — VIA Apollo KT133 (VT8363+VT82C686A)
RAM — Up to 1.5 GB in three DIMM (168 pins, 3.3 V), PC100/133 SDRAM, 100/133 MHz frequency
BIOS — Award Plug-and-Play BIOS
Titan TTC-D2T was used as a processor cooler (Fig. 18.70). This cooler ensures efficient cooling of Thunderbird-based Athlon and Duron. The fan is controlled by the built-in hardware-monitoring tools of the VT82C686A chip.
Figure 18.70: Titan TTC-D2T cooler
The processor temperature is controlled using thermal sensors built into the motherboard and hardware-monitoring tools. The sensors in Soltek SL-75KV+ are flexible (Fig. 18.71); those in Abit KT7 are rigid (Fig. 18.72).
Figure 18.71: Flexible thermal sensor on the Soltek SL-75KV+ motherboard
Figure 18.72: Rigid thermal sensor on the Abit KT7 motherboard
When using the Soltek SL-75KV+ motherboard, the clock frequency of the processor bus is set via one of the two DIP switches (SW1, marked in Fig. 18.73) and via BIOS Setup.
Figure 18.73: DIP switches on the Soltek SL-75KV+ motherboard (SW1 is marked)
For Abit KT7, the frequency is selected in BIOS Setup via SoftMenu. When working with this motherboard, better results were obtained: The FSB clock frequency was increased to 115 MHz, as shown in Tables 18.32 and 18.33 and in Figs. 18.74–18.77.
Processor frequency = bus frequency × multiplier | CPUmark 99 rating | FPU WinMark rating |
---|---|---|
600 MHz = 100 × 6 | 51.4 | 3,260 |
672 MHz = 112 × 6 | 57.8 | 3,660 |
690 MHz = 115 × 6 | 59.4 | 3,760 |
Processor frequency = bus frequency × multiplier | CPUmark 99 rating | FPU WinMark rating |
---|---|---|
600 MHz = 100 × 6 | 52.7 | 3,260 |
630 MHz = 105 × 6 | 55.4 | 3,430 |
672 MHz = 112 × 6 | 59.1 | 3,660 |
Figure 18.74: Duron 600 (Abit KT7) after increasing the bus frequency (CPUmark 99)
Figure 18.75: Duron 600 (Abit KT7) after increasing the bus frequency (FPU WinMark)
Figure 18.76: Duron 600 (Soltek SL-75KV+) after increasing the bus frequency (CPUmark 99)
Figure 18.77: Duron 600 (Soltek SL-75KV+) after increasing the bus frequency (FPU WinMark)
Almost all contemporary processors are manufactured with fixed frequency multipliers. Nevertheless, with AMD processors, motherboards such as Soltek SL-75KV+ and Abit KT7 allow the multiplier to be changed. This is possible only with processors that have intact L1 bridges, located on the surface of the processor case.
If the L1 bridges on the processor case are cut, it is possible to restore the capability of changing the multiplier by closing the contacts. This operation can be accomplished easily, using a soft sharpened pencil with graphite, which has high conductivity. To restore disabled overclocking capabilities, rub the cut L1 bridges on the processor, pressing the pencil tight into the gaps to make small "hills." When performing this operation, avoid closing contacts between adjacent bridges. To control this operation visually, use a powerful magnifying glass and adequate lighting. Also, make sure that you observe all measures necessary to protect the processor from static electricity.
The results of restoring the conductivity of the L1 bridges are shown in Figs. 18.78 and 18.79, which illustrate fragments of the Duron surface.
Figure 18.78: Initial state of the L1 bridges on the Duron surface
Figure 18.79: L1 bridges with restored contacts on Duron
After restoring the cut bridges on Duron, it becomes possible to change the frequency multiplier using the built-in functionality of the motherboards.
For Soltek SL-75KV+, the multiplier was chosen using the appropriate DIP switch (SW2, marked in Fig. 18.80).
Figure 18.80: DIP switches on the Soltek SL-75KV+ motherboard (SW2 is marked)
Overclocking results, as well as the chosen modes, are presented in Tables 18.34 and 18.35 and in Figs. 18.81–18.84.
Processor frequency = bus frequency × multiplier | CPUmark 99 rating | FPU WinMark rating |
---|---|---|
600 MHz = 100 × 6.0 | 51.4 | 3,260 |
650 MHz = 100 × 6.5 | 55.0 | 3,550 |
700 MHz = 100 × 7.0 | 57.6 | 3,810 |
800 MHz = 100 × 8.0 | 63.2 | 4,350 |
850 MHz = 100 × 8.5 | 65.8 | 4,640 |
900 MHz = 100 × 9.0 | 68.3 | 4,900 |
Processor frequency = bus frequency × multiplier | CPUmark 99 rating | FPU WinMark rating |
---|---|---|
600 MHz = 100 × 6.0 | 52.7 | 3,260 |
650 MHz = 100 × 6.5 | 55.9 | 3,530 |
800 MHz = 100 × 8.0 | 65.0 | 4,350 |
Figure 18.81: Duron 600 (Abit KT7) after changing the multiplier (CPUmark 99)
Figure 18.82: Duron 600 (Abit KT7) after changing the multiplier (FPU WinMark)
Figure 18.83: Duron 600 (Soltek SL-75KV+) after changing the multiplier (CPUmark 99)
Figure 18.84: Duron 600 (Soltek SL-75KV+) after changing the multiplier (FPU WinMark)
Maximum performance levels are achieved by choosing the optimal processor-bus frequency at the best value of the frequency multiplier.
Test results obtained when overclocking the processors on both motherboards are provided in Tables 18.36 and 18.37 and in Figs. 18.85–18.88.
Processor frequency = bus frequency × multiplier | CPUmark 99 rating | FPU WinMark rating |
---|---|---|
600 MHz = 100 × 6.0 | 52.7 | 3,260 |
630 MHz = 105 × 6.0 | 55.4 | 3,430 |
650 MHz = 100 × 6.5 | 55.9 | 3,530 |
672 MHz = 112 × 6.0 | 59.1 | 3,660 |
683 MHz = 105 × 6.5 | 58.8 | 3,720 |
715 MHz = 110 × 6.5 | 61.6 | 3,890 |
800 MHz = 100 × 8.0 | 65.0 | 4,350 |
840 MHz = 105 × 8.0 | 68.4 | 4,580 |
Processor frequency = bus frequency × multiplier | CPUmark 99 rating | FPU WinMark rating |
---|---|---|
600 MHz = 100 × 6.0 | 51.4 | 3,260 |
650 MHz = 100 × 6.5 | 55.0 | 3,550 |
672 MHz = 112 × 6.0 | 57.8 | 3,660 |
683 MHz = 105 × 6.5 | 57.4 | 3,720 |
690 MHz = 115 × 6.0 | 59.4 | 3,760 |
700 MHz = 100 × 7.0 | 57.6 | 3,810 |
715 MHz = 110 × 6.5 | 60.2 | 3,890 |
748 MHz = 115 × 6.5 | 63.2 | 4,080 |
770 MHz = 110 × 7.0 | 63.5 | 4,190 |
800 MHz = 100 × 8.0 | 63.2 | 4,350 |
840 MHz = 105 × 8.0 | 66.7 | 4,580 |
850 MHz = 100 × 8.5 | 65.8 | 4,640 |
880 MHz = 110 × 8.0 | 69.9 | 4,790 |
893 MHz = 105 × 8.5 | 69.4 | 4,860 |
896 MHz = 112 × 8.0 | 71.2 | 4,880 |
900 MHz = 100 × 9.0 | 68.3 | 4,900 |
910 MHz = 107 × 8.5 | 70.9 | 4,980 |
Figure 18.85: Duron 600 (Soltek SL-75KV+) after combined overclocking (CPUmark 99)
Figure 18.86: Duron 600 (Soltek SL-75KV+) after combined overclocking (FPU WinMark)
Figure 18.87: Duron 600 (Abit KT7) after combined overclocking (CPUmark 99)
Figure 18.88: Duron 600 (Abit KT7) after combined overclocking (FPU WinMark)
Maximum performance is achieved with the maximum multiplier and maximum bus frequency.
With the Abit KT7 motherboard, it was possible to achieve better results: The processor frequency was increased more than 1.5 times. Maximum performance of integer calculations was achieved in the following mode: 896 MHz = 112 × 8. For floating-point calculations, the most efficient mode had a CPU frequency of 910 MHz.
To achieve high frequencies, the CPU core voltage and input/output circuits had to be increased. Tables 18.38 and 18.39 specify the modes in which the voltage was raised.
Processor frequency = bus frequency × multiplier | Core voltage / I/O (V) | Temperature (°C) |
---|---|---|
600 MHz = 100 × 6.0 | 1.50/3.30 | 37 |
770 MHz = 110 × 7.0 | 1.60/3.40 | 41 |
850 MHz = 100 × 8.5 | 1.65/3.40 | 44 |
880 MHz = 110 × 8.0 | 1.70/3.40 | 47 |
893 MHz = 105 × 8.5 | 1.70/3.40 | 48 |
900 MHz = 100 × 9.0 | 1.75/3.40 | 50 |
910 MHz = 107 × 8.5 | 1.75/3.40 | 50 |
Processor frequency = bus frequency × multiplier | Core voltage/I/O (V) | Temperature (°C) |
---|---|---|
600 MHz = 100 × 6 | 1.5/3.3 | 37 |
840 MHz = 105 × 8 | 1.6/3.4 | 43 |
Some overclocking attempts resulted in failures: The POST routine couldn't be accomplished successfully, the operating system wouldn't boot, or the computer hung up during the test. Variants in which at least the POST routine could be accomplished successfully are described in Table 18.40. From these data, it follows that, in most cases, the problem of unstable operation could be solved by increasing the core supply voltage. This increase would ensure a higher operating frequency of the processor. However, this seriously increases the risk of damaging the processor.
Processor frequency = bus frequency × multiplier | Voltage (V) | POST routine | Windows | WinBench test |
---|---|---|---|---|
893 MHz = 110 × 8.5 | 1.650 | Passed | Didn't boot (IOS error) | Not performed |
893 MHz = 110 × 8.5 | 1.675 | Passed | Didn't boot | Not performed |
893 MHz = 110 × 8.5 | 1.700 | Passed | Booted | Passed |
800 MHz = 100 × 9.0 | 1.700 | Passed | Booted | Failed |
800 MHz = 100 × 9.0 | 1.750 | Passed | Booted | Passed |
927 MHz = 103 × 9.0 | 1.750 | Passed | Didn't boot | Not performed |
935 MHz = 110 × 8.5 | 1.750 | Passed | Didn't boot | Not performed |
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