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PCB Design and Specifications

The graphics card is rather heavy and doesn’t look like a regular ATI Radeon HD 5870. It is more like the ASUS Matrix GTX285, at least visually. The protrusion in the top part of the card contains LEDs to highlight the letters “Matrix” on the card’s butt-end. They are also part of a special diagnostic system. This protrusion may provoke some problems with the installation of the card into short system cases but such top-end products as the ASUS Matrix 5870 are usually accommodated in huge premium-class gaming chassis.


Asus Matrix 5870 (left), ATI Radeon HD 5870 reference (right)

It is next to impossible to see anything interesting in the graphics card’s design with its cooler in place because even the reverse side of the PCB is covered with a metallic plate. We can only spot an ASUS Super Hybrid Engine chip which constitutes the hardware part of the control system. There are also a row of ProbeIt contact points in the top part of the PCB. You can use them to measure the card’s key voltages with a multimeter. Let’s now strip the card of its cooler and take an indecently closer look at it.


Asus Matrix 5870 (left), ATI Radeon HD 5870 reference (right)

If there is any resemblance, it is only because all graphics cards of the same class and dimensions look similar. The power section of the ASUS product is awe-inspiring. There are as many as eight phases for the GPU alone. There are also a couple of 2-phase voltage regulators for the memory chips and the GPU’s auxiliary circuitry.

The GPU voltage regulator is based on a 12-channel uP6208 controller from uPI Semiconductor. The uP6205 chip you can see next to it is responsible for the graphics memory. This pair of chips was also used on the ASUS Matrix GTX285, by the way. A second such chip with accompanying power components is located near the CrossFire connectors. The graphics card has two 8-pin PCIe 2.0 power connectors but has no protection against your connecting two 6-pin power cables to them (and works normally in this case).

As we wrote above, the protrusion at the top of the cooler’s casing contains a few multicolored LEDs which highlight the word “Matrix” you can see nearby. The color of the highlighting depends on the current GPU load and varies from green to red. It is most often blue, indicating medium load, as in the photo. This feature should be appreciated by people whose system case has a side window, but it has little functional worth. The highlighting won’t be visible at all in an ordinary system case.

The Matrix 5870 carries a double amount of local graphics memory, 2 gigabytes, so it has twice the usual number of GDDR2 chips which are placed on both sides of the PCB, eight chips on each side. These K4G10325FE chips from Samsung have a capacity of 1 Gb (32 Mb x 32), the HC04 suffice denoting a rated frequency of 1250 (5000) MHz. AMD’s reference card uses the same memory and has the same memory frequency like the ASUS Matrix 5870, namely 1200 (4800) MHz. We’ll check out its overclocking potential soon.

The GPU is neither new nor exceptional. It is a regular RV870 Cypress with an open die and an incomprehensible marking. It was manufactured on the 50th week of 2009. The GPU is overclocked from the reference frequency of 850 MHz to 900 MHz but GPU-Z reports 894 MHz due to the specifics of the clock generator’s operation. The GPU frequency can be lowered to 600 or 300 MHz in power-saving modes: the first mode is for such tasks as HD video decoding while the second one, for desktop applications. The default GPU voltage is 1.15 volts but the ASUS Matrix 5870 offers virtually unlimited opportunities to increase it. Using iTracker 2, we easily increased the voltage to 1.4 volts. We stopped at that value to avoid any risks and because we couldn’t get any overclocking benefits from increasing the GPU voltage more.

The ASUS Matrix 5870 has only one DVI-I connector (it supports analog connection, too). It also has one DisplayPort and one HDMI connector. Although this selection of interfaces is quite up to date, the card does not allow to easily use three DVI-interfaced monitors simultaneously although this feature is implemented in AMD’s GPUs. You’ll have to purchase a DisplayPort à DVI-D adapter for a third monitor which costs from $12 to 30. ASUS might have included such a cheap adapter into the box. Besides, the HDMI à DVI-D adapter doesn’t sit firmly in the card’s connector when the cable is attached to it.

The Safe Mode button can help restore the card to life in case you’ve set too high frequencies. This hardware solution is necessary because the changed values of frequencies and voltages are written right into the BIOS of the card. Pressing the Safe Mode button rolls the card back to its failsafe factory BIOS settings. This is a very handy feature that may be of much help for overclockers, but you shouldn’t forget that it cannot restore the card if your too-high voltage/frequency settings have physically damaged the latter.

Nothing special can be expected from the cooling system installed on the ASUS Matrix 5870. It represents the time-tested classic design with a centrifugal fan. The hot air is exhausted outside through the slits in the card’s mounting bracket. This cooler design is employed on each fast graphics card from both AMD and Nvidia, its specific implementations varying but slightly in such details as the size of heatsinks, the model of the fan, and the thermal interface for the GPU die.

The cooling system installed on the ASUS Matrix 5870 has a higher-performance fan than the reference cooler. It features direct-touch technology: the heat pipes are flattened and polished off and contact the graphics core directly. In theory, this helps minimize the loss of heat as it is being transferred from the cooler’s sole to the heat pipes. However, the RV870 die is rather large and has no heat-spreading cap, and the trace of the thermal grease makes it clear that the two outermost pipes out of the total five do almost nothing. This design flaw may have a negative effect on the performance of this otherwise thought-through cooler. Besides, the direct-touch technology leaves the row of memory chips above the GPU without any cooling whereas the memory chips on the right have contact with the cooler’s base through an elastic thermal pad. Another such thermal pad is used to dissipate heat from the power system components. By the way, the frame that all of the cooler elements are mounted on is a sheet of metal rather than a massive cast frame as in some other coolers. Its thermal capacity is lower, so it may cool the auxiliary components less effectively.

We don’t have many complaints about the heatsink. It is a standard thing consisting of thin aluminum fins fitted on the heat pipes and soldered to them. The heatsink is large enough to cope with an RV870 even if the latter is overclocked. So, we only have some apprehensions about the two outermost heat pipes which do not do much work.

Overall, the cooling system installed on the ASUS Matrix 5870 seems to be able to cope with its job, yet it is not free from certain flaws which may affect its performance negatively. We will discuss the noise factor in the next section but we want to note that Gigabyte avoided the abovementioned drawbacks using a simpler cooler. A more complex solution is not necessarily the best one.

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