Table 2. Effect Of Memory Bandwidth On Performance; Table 3. Effect Of Memory Latency On Performance - AMD 3800 - Processor - 1 x Athlon 64 Evaluation Manual

30579 Rev. 3.74 March 2007
For discrete graphics configurations, memory bandwidth has a smaller impact on
end performance. For example, changing from dual-channel to single-channel
memory (halving the marketed bandwidth) on an otherwise identical system
reduces performance only 2-3% (see

Table 2. Effect of Memory Bandwidth on Performance

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Computer Gaming
Memory latency is more critical to performance. As
AMD Athlon™ 64 FX-62 dual-core processor with DDR2-800 memory has
approximately 4% better performance than an AMD Athlon 64 FX-60 dual-core
processor with DDR1-400 memory. In general, each 5-10% reduction in latency
improves performance by 1-2%.

Table 3. Effect of Memory Latency on Performance

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Digital Media
Computer Gaming
• An advanced HyperTransport™ technology link (see
– Dramatically improves I/O bandwidth, enabling faster access to peripherals such
as hard disk drives, USB 2.0, and gigabit Ethernet cards.
– Data compression benchmarks illustrate higher processor performance due to a
reduced I/O interface throttle.
• Large first-level (L1) and second-level (L2) on-die caches
– 128 KB of L1 cache and 1 MB of L2 cache allow the AMD Athlon 64 processor to
excel at performing matrix calculations on arrays.
– Benchmarks that use intensive, large matrix calculations benefit from having the
entire matrix available in the L2 cache.
• Processor core clock-for-clock improvements
– Larger translation look-aside buffers (TLB) with reduced latencies.
– A global history counter with four times the number of bimodal counters as seventh-
generation processors, to improve branch prediction.
– These features drive IPC improvements and provide a more efficient pipeline for
CPU-intensive applications.
– CPU-intensive games such as Unreal Tournament benefit from these core
improvements.
AMD Athlon™ 64
Processor 3800+,
Dual-Channel Memory
101.3%
101.9%
104.1%
Overall 102.4%
AMD Athlon™ 64 FX-62
Dual-Core Processor,
DDR2-800
103.5%
105.6%
104.5%
Overall 104.6%
AMD64 Single Socket Processor Architecture
AMD Processor Performance Evaluation Guide
Table 2).
AMD Athlon 64
Processor 3800+,
Single-Channel Memory
100.0%
100.0%
100.0%
100.0%
Table 3
AMD Athlon 64 FX-60
Processor,
DDR1-400
100.0%
100.0%
100.0%
100.0%
Figure
shows, an
2)
15