SiS 756: PCI Express for AMD Socket 939
by Wesley Fink on September 13, 2005 12:05 AM EST- Posted in
- CPUs
Basic Features: SiS 756 Reference Board
In Reference Board reviews, there is always the mention that Reference Boards are designed for qualification and not for production. This is particularly true with the SiS 756 Reference Board as it was not even designed to fit in a standard case.
200 to 255 is too limited in processor clock speed to interest the enthusiast, though it is more than adequate for the average user who may never overclock his motherboard. Particularly troublesome is the missing 600 Hypertransport setting, which is useful in higher overclocks. Voltage is also limited to a modest .05V over-volt with a 130nm Athlon 64.
The 965L south bridge supported a Realtek ALC850 7.1 channel codec that is commonly seen on AMD chipsets. However, the more recent 966 south bridge, combined with the 756, could provide High-Definition (Azalia) audio, like the recently tested ATI Rx480 chipset. This would be a real advantage compared to the basic audio capabilities of the nForce4 chipset.
You will also notice that while the 965L supports SATA and SATA RAID, it does not support SATA2. This may or may not matter to you. SATA2, and in particular SATA2 3.0Gb/s drives, are just now appearing on the market. The new SATA2 drives, even the 3Gb/s variety, offer little performance advantage today, so this may not of importance to you. However, this will likely become a more important feature over time.
It is also worth noting that SiS has not yet announced a Southbridge with SATA2 support. Even the 966 family does not fully support SATA2. The next generation south bridges will likely support this feature.
| SiS 756 Reference Board | |
| CPU Interface | Socket 939 Athlon 64 |
| Chipset | SiS 756 Northbridge - SiS 965L Southbridge |
| CPU Clock Speeds | 200 to 255MHz in 1MHz Increments |
| Memory Speeds | Auto, DDR200, 266, 300, 366, 400 |
| PCIe Speeds | 80, 85, 90, 91, 94, 97, 100 |
| PCI/AGP | Fixed at 33/66 |
| Core Voltage | Auto, 1.175V to 1.55V in 0.025V increments |
| CPU Clock Multiplier | 8x-23x in 1X increments |
| DRAM Voltage | NO Adjustments |
| HyperTransport Frequency | 1000MHz (1GHz) |
| HyperTransport Multiplier | Auto, 200, 400, 800, 1000 (NO 600 Setting) |
| HyperTransport Voltage | None |
| Chipset Voltage | None |
| Memory Slots | Four 184-pin DDR DIMM Slots Dual-Channel Configuration Regular Unbuffered Memory to 4GB Total OR Registered DIMMs if Selected in BIOS |
| Expansion Slots | 1 PCIe x16 2 PCIe x1 2 PCI Slots |
| Onboard SATA/RAID | 4 SATA 1 Drives by 965L (RAID 0, 1, JBOD) |
| Onboard IDE/IDE RAID | Two Standard ATA133/100/66 (4 drives) |
| Onboard USB 2.0/IEEE-1394 | 8 USB 2.0 ports supported by 965L NO Firewire |
| Onboard LAN | Gigabit PCIe Ethernet by SiS191/190 Driver |
| Onboard Audio | 7.1 AC'97 Audio by Realtek ALC850 |
| BIOS | AMI |
In Reference Board reviews, there is always the mention that Reference Boards are designed for qualification and not for production. This is particularly true with the SiS 756 Reference Board as it was not even designed to fit in a standard case.
Click to enlarge.
200 to 255 is too limited in processor clock speed to interest the enthusiast, though it is more than adequate for the average user who may never overclock his motherboard. Particularly troublesome is the missing 600 Hypertransport setting, which is useful in higher overclocks. Voltage is also limited to a modest .05V over-volt with a 130nm Athlon 64.
The 965L south bridge supported a Realtek ALC850 7.1 channel codec that is commonly seen on AMD chipsets. However, the more recent 966 south bridge, combined with the 756, could provide High-Definition (Azalia) audio, like the recently tested ATI Rx480 chipset. This would be a real advantage compared to the basic audio capabilities of the nForce4 chipset.
You will also notice that while the 965L supports SATA and SATA RAID, it does not support SATA2. This may or may not matter to you. SATA2, and in particular SATA2 3.0Gb/s drives, are just now appearing on the market. The new SATA2 drives, even the 3Gb/s variety, offer little performance advantage today, so this may not of importance to you. However, this will likely become a more important feature over time.
It is also worth noting that SiS has not yet announced a Southbridge with SATA2 support. Even the 966 family does not fully support SATA2. The next generation south bridges will likely support this feature.
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PrinceGaz - Tuesday, September 13, 2005 - link
Yeah, after hearing in an earlier comments section here about all the problems with ActiveArmor and checking on the relevant forums, I decided against it. Then I found that nVidia's IDE/SATA drivers are also notorious, and for me they made it impossible to load Windows after installing, so I have to unselect them when installing the chipset driver and just stick with the standadrd Windows ones. That's with the 6.66 driver that was the latest when I last checked.nVidia really need to sort their chipset drivers out, they may make good hardware but that is useless if the software to make it works is bug-ridden.
nserra - Tuesday, September 13, 2005 - link
Well always criticizing about the mobos doesn’t do more than 220Mhz/230Mhz, but when do you test this?When I will see some nforce3 Ultra/ULi M1695 doing 300Mhz or more on Sempron(2600+/2800+)/Athlon(3000+) to test how good are they for overclocking?
I mean this AMD Athlon 64 4000+ (2.4GHz) Socket 939 is useless to know this (i think).
When i will see a 2600 sempron going from 1.6Ghz go to 2.6Ghz? Or Athlon 1.8Ghz going 2.4Ghz or more.
How good are this new mobos that can do 400Mhz like Uli? I mean I need more HTT speed to overclock more right?
1.6Ghz (200Mhz) vs 2.4Ghz (300Mhz) vs [3.2Ghz (400Mhz)|Impossible]
Only Xbit does real OC tests on the web, not just theorical ones?
Wesley Fink - Tuesday, September 13, 2005 - link
The 4000+ we use for testing OC is known to OC as high as 245 on some motherboards. Our test memory has gone as high as 318 at 1:1 on some motherboards, by lowering the CPU multiplier. If there are other factors, like no memory voltage adjustments, we will also lower the memory divider (and performance) to determine the highest clock frequency OC. By lowering the memory ratio our CPU/memory has done as high as 400 Clock frequency on some boards. With this envelope of known OC values with this CPU and memory we test each motherboard we review. This provides real information on overclocking capabilities COMPARED to other motherboards.A "review" with just one set of numbers, whether overclocking or benchmarks, is nothing more than an advertisement. A REVIEW requires comparison of the SAME EXACT TESTS on two or more boards, IMO. Picking memory ratios out of the air for OC tests will generate high OC numbers, but those numbers tell you nothing about overclocking performance compared to other boards.
nserra - Tuesday, September 13, 2005 - link
OK. I though you would need an FX processor to do that.Wesley Fink - Tuesday, September 13, 2005 - link
All Athlon64 processors are unlocked DOWN (below the rated multiplier). On a 4000+, 12X is the stock multiplier, but you can select 12x, 11x, 10x, 9x, 8X on if the motherboard supports multipliers (and almost all A64 motherboards do). The FX is unlocked UP and DOWN , so you can also select higher multipliers like 13x, 14x, etc. with an FX53 which also runs at 12x like the 4000+.The down unlock is really a by-product of Cool'n'Quiet, as AMD implements cool'n'quiet as a drop to lower multipliers when overheating occurs.
Palek - Tuesday, September 13, 2005 - link
On page 5 in the memory stress testing section:"This points to SiS having a poorer front end to the ATI on-chip memory controller than either nForce4 or ATI Rx480."
That should be AMD on-chip memory controller.
Wesley Fink - Tuesday, September 13, 2005 - link
How right you are. Corrected . . .Furen - Tuesday, September 13, 2005 - link
Horrible... I guess all those 300+HTT mobos have me spoiled.hermitthefrog - Tuesday, September 13, 2005 - link
It just makes me wonder because the average person who normally buys an off-the-shelf doesn't care if it is a socket 754 or 939 or whatever, as these things don't mean much except to the gamers and power users that would typically build their own systems. SiS usually seems to cater to the OEM systems where the PC manufacturer is more concerned about a price point and basic performance and the end-user doesn't care what chipset is in his machine. All he cares about is probably "Well it a Pentium 4 or it is 3000 mhz" or whatever because this is obvious. So if SiS is going to bother to make a chipset to compete with the NForce 4 they should realize what makes the NForce 4 so popular- ever since the NForce2, gamers and the like have associated Nforce with top performance and cutting edge features. And obviously the Nforce 4 is better than the Nforce 2 or 3! I know some of my friends and I who used to have Athlon XP's and Nforce 2 based boards would naturally love to get our hands on the latest and greatest Nforce 4/Athlon 64 systems because to us it is a sure thing and it has a cool name to boot. Meanwhile ATI and SiS and VIA all have cryptic chipset names that don't elicit an emotional response like the "NForce" did. I guess the point I am trying to make is that Nvidia's competitors are not as marketable, and the products aren't as "edgy or daring" sounding and this is why they are all getting trounced sales-wise (production and design and availability problems ahem non-withstanding) and the fact that Nvidia actually delivers when they say they will. I am not a fan boy but this is all obvious from watching for the couple years.ceefka - Tuesday, September 13, 2005 - link
Plus you'd be hardpressed to find the features of the nF4 on another chipset. While SiS, ATI, VIA and ULi may be getting there, they offer just about nothing that you can't get from an nF4.