Newtun said:
I think the ASUS has the BIOS multiplier-unlocking feature. I wonder how its chipset heat sink compares with the cheepset fan on the Epox.
The EPoX doesn't have any fan on the north bridge, just a relatively big passive heatsink. According to many, this passive heatsink is what's holding back the board when trying to reach very high FSB frequencies. Nonetheless, it generally clocks higher than most other boards based on the nForce2 chipset.
Newtun said:
Woops! I just checked Newegg, and they are sold out of the Epox, but they have the Soltek version in. I'll go check for reviews of that one, since Soltek has a pretty good reputation for quality.
First of all, I wouldn't buy the Asus A7N8X or the Soltek SL-75FRN-L. The reason? dual phase power circuitry :
[url=http://www.lostcircuits.com/motherboard/soltek_sl75frnl/4.shtml said:
Lost Circuit[/url]] The only issue pertaining to the number of phases is the switching frequency. That is, because of trace impedance and related issues, e.g. the choice of MOSFET, there is a certain limit to how fast every phase can switch. Two phases that are shifted will double the switching frequency, three phases will triple it and so on. The underlying principle is very similar to the difference between a 4-cylinder and a 6-cylinder engine and the above mentioned cost savings argument would be equivalent to claims of reduced cost based on reduced counterweights on the crankshaft. In order to reduce the switching ripples, a commonly used practice is to different upper and lower MOSFETs with one being faster, and the other one a bit slower for a staggered onset.
There is, however, no substitute for multiple phases, since all improvements done on a 2-phase design can also be implemented on higher number of phases, albeit at greater cost. To compensate for the coarser granularity, and higher delays in switching, often enough a small offset in voltage is being used, meaning that the default voltage is set slightly higher than necessary so that even negative spikes can be absorbed more easily. The last issue in this respect is where the VRM gets its power from in the first place. Lately, we have seen a tendency to use the dedicated auxiliary 12 V rails to supply CPU power to the board instead of plugging into the board power supplied by the standard 20 pin ATX connector. In general, this is a good thing but if the system PSU has fluctuations on the 12V rail, those will be propagated to the CPU unless heavy duty buffering and filtering is applied.
So all in all, you're better off with a triple-phase design. You can be fine with a dual-phase, but only if it has been very well made by the board manufacturer. And no, it's not because it's Asus that it's automatically good. There are also concerns about the long-term reliability of dual-phase power circuits versus triple-phase, since the former has to share the load on only two transistors instead of three. To summarize, a triple-phase power circuitry means less risks and removes a lot of "if".
The 12V rail addition is a nice bonus too. The only nForce2 motherboard I have seen with both a triple-phase power circuit and a 12V rail is the Abit NF7. It doesn't mean it's perfect, but it should be among the most reliable. However, Abit has a tumultuous history regarding long term reliability, mostly because of the tendency of many of their past motherboards to use cheap capacitors that were prone to leak with the time. A look at the layout of the NF7 tells me that it shouldn't be the case since there are a lot of big capacitors on it, so none should be overcharged.
Here's my list of Pro and Cons for the nForce2 boards I have seen so far :
- Asus A7N8X & Deluxe :
Pricey
Dual-phase power circuitry
No P4-like 12V rail
Abit NF7 & NF7-S
Cheaper than Asus and Chaintech, but dearer than most others
Abit's history of leaky capacitors
FIC AU11
Like the EPoX, 10$ cheaper
No SoundStorm support (no SPDIF and ACR for 5.1 output), although it uses MCP-T
Passive north bridge heatsink
No 12V rail
Superior overclocking results nonetheless
EPoX EP-8RDA & 8RDA+
Passive north bridge heatsink
No 12V rail
Superior overclocking results nonetheless
Chaintech 7NJS
Too expensive
C-Media audio controller instead of nForce APU.
No 12V rail
dual-phase power circuitry
I don't like it, period.
Leadtek K7NCR18D & Pro
Cheap
Not the best overclocker
Passive north bridge heatsink
No 12V rail
MSI K7N2-L
dual-phase ...
has the 12V rail though
Not a great overclocker
Passive north bridge heatsink
Like most things from MSI : average
IMO, there are better products elsewhere
Soltek SL-75FRN-L
No SoundStorm support (MCP not-T south bridge)
dual-phase...
has the 12V rail
From the few reviews I read, very optimized timings.
Yellow, I mean, come on.
This list is far from being complete. Just my first impressions on each motherboards.
The best values are, always according to my little opinion :
- Abit NF7-S
FIC AU11
EPoX EP-8RDA+
Leadtek K7NCR18D Pro
Each of them has apparently a good power circuitry and has a lot of bang for the buck. The Leadtek is good if you don't plan to overclock. FIC is the cheapess board if you want good overclocking potential, but couldn't care less for fancy features. The Abit and EPoX are the most full-featured boards with an acceptable price and with few short-comings.
Disclaimer : Should I need to repeat it, this is only my personal view on it.
