Why sis645/DX/648 over 845?

[comrade]

What would be some reasons for 6xx over 845 other than the price factor?
Is it more stable than 845?
Performance wise?

Any comment is appreciated.

 

[GTaudiophile]

Performance is on par or slightly better, but i845 might be more stable. I've had my i845D (ASUS P4B266) since January, and I've had zero BSODs. With that said, you might be wise to wait for Granite Bay or SiS's DC DDR solution.

 

[Athlon4all]

First off, SiS 648 has AGP8X, USB2 and Firewire in the chipset.

Secondly (and for me more importantly), SiS 648 with DDR333 is the closest chipset to 850e+PC1066 (>5%). A key factor in the 845 vs 64x comparision is whether DDR333 or DDR266 is being used. i845D, i845E do not support DDR333. 845G does unoffically, 845GE/PE both offically support it. Bottom line, without DDR333, the i845 series is spanked by 850e and 648/P4X400.

 

[oldfart]

i845D, i845E do not support DDR333. 845G does unoffically, 845GE/PE both offically support it. Bottom line, without DDR333, the i845 series is spanked by 850e and 648/P4X400.

The 845D/E unofficially support DDR354, as does 845PE. There are tons of people here running DDR400 - DDR440 with complete stability on i845x chipsets. This can not be said of the others. VIA P4X400 is a joke. Just try and run DDR400 with stability on that thing. The 845 boards offer great stability and overclocking features such as a PCI/AGP lock. The 845 is hardly spanked by the others. Its the other way around.

Anandtech:
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However, some problems cropped up once we started testing DDR400 memory. First off, one of the 3 DIMM slots was completely unable to operate DDR400; it wouldn't even boot into Windows XP. We don?t know the exact cause for this malfunction, but we are working with VIA to pinpoint the issue.

Despite this anomaly, we were able to operate the DDR400 memory in the other two DIMM slots available on the P4PB 400. With DDR400 in either of the two slots, we were able to boot into Windows XP and run some of the stress tests and benchmarks we needed for DDR400 scores. Unfortunately, the P4PB 400 failed to complete SYSMark 2002 among other benchmarks, even after several tries. But even though the DDR400 memory was mostly operational using the 2 other slots, it definitely wasn't as trouble free as we would have preferred (random crashes and reboots galore).
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THG:
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About two weeks ago, we had planned to test the VIA P4X400 chipset, which is also supposed to support DDR400. However, during the test, problems emerged with a memory clock of 200 MHz: even in the slowest CL3 mode, the P4X400 board was not able to boot, and the system hung with the port 80 error "C1" (memory error). So we weren't able to test the P4X400 at 200 MHz memory clock (DDR400). The Soltek SL-85ERV brings us new hope, and we expect to take a close look at it in one of the up-coming tests.
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xbitlabs:
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Anyway, the P4PB 400 mainboard disappointed me with its unstable operation with DDR400 memory. Moreover, with default settings P4PB 400 performed worse with DDR400 than with DDR333. And this situation is very hard to change for the better even during fine tuning. VIA comments on this as follows: "As DDR400 standard is not ratified, we increase the timings greatly to ensure stable work and it inevitably leads to lower performance". Well, quite reasonable, I should say.

The latency measurements show that VIA P4X400 with DDR400 SDRAM will not please us with good results. Memory subsystem latency is greatly increased in this case and it means that VIA didn't care about optimizing its controller for DDR400. That is, by the way, one more argument proving that VIA P4X333 and P4X400 are one and the same thing.

When encoding video into MPEG-4 format, VIA P4X400 managed to fall behind all its rivals, even those, which worked with slower memory. The only conclusion is that the VIA chipset may hardly be considered able to work with DDR400. Actually the support of this memory type is nothing but a marketing trick.
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