X-bit labs

Your Value 64 Bits: AMD Sempron 3400+ CPU Review (page 3)

Category: CPU

by Ilya Gavrichenkov

[ 08/29/2005 | 12:14 PM ]

Overclocking

People often buy Semprons to overclock them and lift their performance up to the level of much more expensive CPUs. So, we just couldn’t skip checking our Sempron 3400+ at higher frequencies.

The Sempron 3400+ has a default clock rate of 2.0GHz, so its frequency multiplier is 10x. Because of Cool’n’Quiet technology, this multiplier can be decreased, but cannot be increased. The default multiplier is quite high, however, for the mainboard not to become a limiting factor at overclocking (we won’t have to heave the frequency of the clock generator up to values like 300MHz). Basing on our experience with other CPUs from AMD on the revision E core, we can expect the highest frequency of the Sempron 3400+ to be about 2.5-2.7GHz, so the mainboard must be stable at clock-generator frequencies of about 250-270MHz. By the way, these frequencies can be achieved even with more than one memory module (to get closer to a 300MHz clock-generator frequency, you usually have to use only one DIMM).

We took a DFI LANPARTY UT nF3 250Gb mainboard for our overclocking experiments. This mainboard enjoys a reputation of one of the best platforms for Socket 754 processors. The system at large was assembled out of the following components:

• Mainboard: DFI LANPARTY UT nF3 250Gb (NVIDIA nForce3 250Gb)
• Cooler: AVC Z7U7414001
• Memory: Corsair CMX512-3200XL (2x512MB, DDR400 SDRAM)
• Graphics card: PowerColor RADEON X800 XT (AGP 8x, 500MHz/500MHz)
• Hard disk drive: Western Digital Raptor WD740GD (Serial ATA-150)

We increased the CPU voltage to 1.5V to get higher results at overclocking. This is not a dangerous measure because the default voltage of the Sempron 3400+ is 1.4V.

Some time ago we experimented with the Sempron 3100+ processor that was based on the E3 revision of the Palermo core (for details see our article called Another Gift to Overclockers: AMD Sempron 3100+ on E Core Revision). We achieved impressive results then, increasing the CPU frequency from the default 1.8GHz to 2.68GHz. This time, however, our revision E6 Sempron 3400+ couldn’t conquer the same clock rate, stopping at 2.6GHz.

The system was perfectly stable at this frequency performing such tests as S&M and Prime95.

We don’t think it is a poor result, though. The CPU frequency gain was 30%, and the clock-generator frequency was 260MHz. We used a 5:4 divider to set the memory frequency at 216.5MHz.

We must acknowledge the highest quality of Corsair’s CMX512-3200XL modules that worked at this frequency with the lowest timings possible (2-2-2-5). This should ensure an additional speed bonus to the overclocked system because, as you perhaps know, the integrated memory controller in K8 processors is exceptionally sensitive to the memory subsystem latency.

Our overclocking results indicate that the frequency potential of the new Palermo core (stepping E6) with enabled AMD64 technology does not greatly differ from that of E3 stepping cores. In other words, overclockers who are into speeding up low-end processors can easily have a 64-bit computer using a new Sempron with enabled AMD64.