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[nextpage title=”Introduction”]

Intel DX58SO (codename “Smackover”) is one of the first socket LGA1366 motherboards for the forthcoming Core i7 processor that Intel will be launching, based on Intel X58 chipset with ICH10R south bridge chip. Let’s take a look at this motherboard and what you should expect from it.

Intel DX58SO SmackoverFigure 1: Intel DX58SO “Smackover” motherboard.

You are probably curious about the new socket LGA1366. On Figures 2 and 3 you can see it in details.

Intel DX58SO SmackoverFigure 2: Socket LGA1366.

Intel DX58SO SmackoverFigure 3: Socket LGA1366.

[nextpage title=”Slots and Extra Power”]

Smackover has two PCI Express 2.0 x16 and one PCI Express 2.0 x4 slots, which can be used to increase the number of video monitors you have installed or to improve gaming performance using CrossFire or SLI modes. Even though the x4 slot is shorter than the x16 slot, you can install a regular x16 card on it, but of course you will be limited to x4 performance. Since the x4 slot is next to the first x16 slot, you can only install single-slot cards on it. So you can have up to three video cards installed on this motherboard.

Intel DX58SO SmackoverFigure 4: Slots.

This motherboard requires extra power to feed the PCI Express slots and two options are available: a standard 4-pin peripheral power connector (Figure 5) or a SATA power connector (Figure 6). This is the first time we’ve seen a motherboard allowing a SATA power connector to be used to provide extra power to the PCI Express slots. Using both at the same time won’t hurt, but only one of the two is required.

The motherboard manual, however, is confusing as to when these connectors should be used. It says “Use of the 1 x 4 auxiliary PCI Express graphics power connector (Figure 30, C) or the SATA-style auxiliary power connector (Figure 30, B) is required with ATX12V power supplies when using PCI Express graphics cards that can consume up to 75 W.” This is confusing because it was clearly written by an engineer. The mention to the 75 W PCI Express limit is really confusing to the average user because he (or she) could assume that the manual is talking about the total consumption of the video card. For example, a GeForce GTX 260 video card consumes 182 W and if you follow exactly what is written on the manual, you would assume that the extra power connector should not be installed when you have a GeForce GTX 260. The manual refers to the amount of power pulled specifically from the PCI Express slot (the rest of the power is pulled from the auxiliary power cable that comes from the power supply and is installed on the video card). The manual should have a table listing which video cards require extra power. This constructive criticism is valid to all motherboard manufacturers, as we always have trouble understanding when extra power connectors should be installed.

We asked Intel to clarify this and their reply was “Whenever using a high performance video card it is a good idea to install one of the connectors, just to be sure that the card is able to get all the power it needs, even when auxiliary power is connected directly to the card.,” which obviously stated what we already knew and didn’t answer our question.

Since connecting the auxiliary power connector won’t hurt, we recommend you to always connect one of them. In fact a safer and clearer instruction would be simply saying to the user to always connect one of the auxiliary power connectors.

Intel DX58SO SmackoverFigure 5: Four-pin peripheral power connector (extra power for video cards).

Intel DX58SO SmackoverFigure 6: SATA power connector (extra power for video cards).

[nextpage title=”Memory Support”]

Core i7 CPUs have an embedded memory controller, just like it happens with AMD processors. All other Intel CPUs use an external memory controller, which is located on the north bridge chip (a.k.a. MCH or Memory Controller Hub) from the chipset. This means that with other Intel CPUs the chipset (and thus the motherboard) is the component that says what memory technologies and the maximum amount of memory you can have on your PC.

Since now the memory controller is inside the CPU, it is the processor, and not the chipset, that defines the memory technologies and the maximum amount of memory you can have. The motherboard, however, may have a limitation as to how much memory can be installed, as it is the case with DX58SO.

The Core i7 integrated memory controller accepts only DDR3 memory (up to 1.6 V; memories that require more than that won’t work and may even damage the CPU) and supports the new triple-channel memory architecture. Even though first Core i7 CPUs officially support up to DDR3-1066, Intel DX58SO supports memories up to DDR3-1333. This is achieved by bypassing the CPU memory clock multiplier (the memory clock is achieved by multiplying a 133 MHz base clock signal).

The triple-channel architecture allows the CPU to access three memory modules at the same time to store or retrieve data, increasing the number of bits that are transferred per clock cycle from 128 (on dual-channel architecture) to 192. Thus this makes a 50% improvement on the maximum theoretical memory bandwidth compared to dual-channel architecture, if both are running at the same clock rate. For example, DDR3-1333 memories running on dual-channel have a maximum theoretical transfer rate of 21 GB/s while on triple-channel they have a maximum theoretical transfer rate of 32 GB/s.

Intel DX58SO has four memory sockets and this may be a problem for the untrained user or technician. In order to achieve the best performance with the Core i7, you should install three identical DDR3 memory modules. In the case of Smackover the sockets where they must be installed are blue. The fourth socket is black and should be used only if you want to increase the amount of memory on your system but sacrificing performance.

For example, if you install four 1 GB modules on this motherboard, the first 3 GB will be accessed at triple-channel performance (up to 32 GB/s if DDR3-1333 modules are used) but the address space between 3 GB and 4 GB will be accessed at single-channel performance (up to 10.6 GB/s if a DDR3-1333 module is used).

With Intel DX58SO you can have up to 16 GB and according to Intel this is a limit for this particular product, not being the limit Core i7 can address.

Intel DX58SO SmackoverFigure 7: Memory modules. Install three modules in the blue sockets for best performance.

[nextpage title=”On-Board Peripherals”]

Intel DX58SO uses the Intel ICH10R south bridge chip, which supports six SATA-300 ports with RAID 0, 1, 10 and 5. In addition to these ports, Intel DX58SO has two eSATA-300 ports on the rear panel, controlled by a Marvell 88SE6121 chip. Notice that no parallel ATA port is available on this motherboard. This board also doesn’t have a floppy disk drive controller.

This motherboard has one Gigabit Ethernet port, which is controlled by the south bridge using one small chip (Intel 82567LM) to make the physical layer interface.

The audio section from this motherboard provides 7.1+2 audio, produced by the south bridge chip with the aid of a Realtek ALC889 codec, which is an outstanding solution, providing an impressive 108 dB signal-to-noise ratio for the analog outputs, 106 dB signal-to-noise ratio for the analog inputs and up to 192 kHz sampling rate for both inputs and outputs. We always complain about the low input signal-to-noise ratio (i.e., 90 dB or below) for the analog input on on-board audio solutions, but Realtek ALC889 is a beautiful exception: you will be able to capture and edit analog audio (e.g., converting LPs to CDs or MP3, converting VHS to DVDs or any other digital format, etc) with this motherboard without adding any background noise.

Even though this motherboard has 7.1 audio, it only provides 5.1 analog audio outputs. But this isn’t a problem, as it has an optical SPDIF output connector and people that want a 7.1 speaker setup will probably buy a set of digital speakers or use a home theater receiver anyway.

This motherboard has 12 USB 2.0 ports with eight of them soldered on the rear panel. Usually motherboards have four or six USB ports on the rear panel, so it is good to see eight of them there, especially because this motherboard does not have traditional mouse and keyboard connectors (PS/2 connectors), so you have to use USB keyboard and mouse. By the way, the ICH10 chip has a feature called “USB Port Disable” that allows you to disable individual USB ports. This is a very interesting feature to have on PCs that are used by several different people to prevent users from installing USB devices (for example, an external hard drive or a USB drive, which can contain viruses and also to prevent people from copying data).

This motherboard also has two FireWire (IEEE1394) ports controlled by a Texas Instruments TSB43AB22A chip, with one soldered on the rear panel and another available through an I/O bracket.

On the connectivity side this motherboard also supports infrared transmitter and receiver, which don’t come with the board.

In Figure 8, you can see the motherboard rear panel with two eSATA-300 ports, eight USB 2.0 ports, one FireWire port, one Gigabit Ethernet port, analog independent 5.1 audio outputs and optical SPDIF output.

Intel DX58SO SmackoverFigure 8: Motherboard rear panel.

As mentioned, this motherboard doesn’t have standard mouse and keyboard connectors (PS/2) and it also doesn’t have parallel and serial ports.

[nextpage title=”Other Features”]Intel DX58SO comes with other smaller features, like an on-board power switch, an on-board buzzer (speaker) and a small 40-mm fan for you to install on top of the passive heatsink from the X58 chip if you think it is heating too much.

Intel DX58SO SmackoverFigure 9: Optional fan for the X58 chip.

The voltage regulator circuit uses solid aluminum capacitors and ferrite chokes, which prevent leakage and have a lower energy loss, respectively, and passive heatsinks on top of the transistors.

Intel DX58SO SmackoverFigure 10: Voltage regulator circuit.

All capacitors that aren’t solid are Japanese, from Chemi-Con, Nichicon and Sanyo, which is terrific.

[nextpage title=”Main Specifications”]

Intel SX58SO (“Smackover”) main features are:

  • Socket: 1366.
  • Chipset: Intel X58 with ICH10R.
  • Super I/O: Winbond WPCD376I
  • Clock generator: SLG505YC264B
  • Parallel IDE: None.
  • Serial IDE: Six SATA-300 ports controlled by the south bridge chip, supporting RAID 0, 1, 0+1 and 5 and two eSATA-300 ports controlled by a Marvell 88SE6121 chip.
  • USB: Twelve USB 2.0 ports (eight soldered on the motherboard and four available through I/O brackets).
  • FireWire (IEEE 1394a): Two ports controlled by Texas Instruments TSB43AB22A chip, one soldered on the motherboard and one available through an I/O bracket.
  • On-board audio: Produced by the chipset together with a Realtek ALC889 codec (eight channels, 24-bit resolution, up to 192 kHz sampling rate for both inputs and outputs, 106 dB signal-to-noise ratio for the inputs and 108 dB signal-to-noise ratio for the outputs), with on-board optical SPDIF connector.
  • On-board video: No.
  • On-board LAN: One Gigabit Ethernet port controlled by the chipset together with an Intel 82567LM chip to make the physical layer interface.
  • Buzzer: Yes.
  • Power supply required: EPS12V.
  • Slots: Two PCI Express 2.0 x16 slots, one PCI Express 2.0 x4 slot, two PCI Express 1.0 x1 slots and one standard PCI slot, supporting CrossFire and SLI.
  • Memory: Four DDR3-DIMM sockets (up to 16 GB up to DDR3-1333/PC3-10600).
  • Number of CDs that come with this motherboard: One.
  • Programs included: motherboard drivers and utilities.
  • Extra features: Aluminum solid capacitors and ferrite chokes on the voltage regulator circuit.
  • Average price in the US: We took a look at this motherboard before it reached the market.

[nextpage title=”Conclusions”]

Intel DX58SO “Smackover” will be one of the first motherboards for the forthcoming Core i7 processors to reach the market.

It simply removes support for all legacy devices: there is no support for parallel ATA devices, PS/2 keyboard, PS/2 mouse, floppy disk drives, serial ports or parallel port.

It provides two x16 and one x4 PCI Express slots, allowing you to install up to three video cards either for having more video monitors or to increase gaming performance by using ATI-based video cards under CrossFire mode. Even though the x4 slot is physically smaller, you can install x16 video cards on it (it will achieve a lower performance compared to an x16 slot, of course).

Even though the first Core i7 CPUs can officially only access memories up to DDR3-1066, Smackover supports the installat
ion of DDR3-1333 memories. This is certainly an advantage for users looking for the highest performance possible. You have to be careful, though, as Core i7 only supports memories working at a maximum 1.6 V. According to Intel if you install memory modules that require more than 1.6 V you can damage the CPU. Intel DX58SO is limited to 16 GB of RAM, which we think is more than enough by today’s standards.

Smackover has four DDR3 sockets and for best performance you should install three identical memory modules. A four-socket configuration isn’t the best for future memory upgrades: if you want to add more memory, you can install a single module on the fourth socket with a sacrifice in performance (the fourth module will be accessed at 1/3 of the maximum possible transfer rate) or you can remove your current three modules and replacing them with three new modules with higher capacities, which represents a higher cost (the price of three new modules with higher capacity plus the cost of having three modules that will be left over – you can sell them on eBay, of course).

So the best option for memory upgrade with Core i7 is to have a motherboard with six memory sockets, because you can add more memory by installing three new memory modules and keeping your old modules installed.

The highlight of this motherboard is its audio codec, with 108 dB signal-to-noise ratio for its analog outputs and 106 dB signal-to-noise ratio for its analog inputs. We always complain that motherboards have a low SNR for the analog inputs, generating too much background noise when you convert analog audio to digital format (e.g., converting VHS tapes, LPs, etc to digital format), a problem that you won’t have with this motherboard.

The overall quality of Intel DX58SO is excellent, with all capacitors being Japanese and the capacitors from the voltage regulator circuit being solid, plus the use of ferrite chokes on the voltage regulator circuit.