Articles: Graphics
 

Bookmark and Share

(2) 
Pages: [ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ]

Design and Functionality

Since the discussed solution belongs to Gigabyte UDV (Ultra Durable VGA) series, it automatically implies that the card is based on a proprietary design. Moreover, the massive heatsink of the graphics cards cooler makes it look considerably longer:

Just like Gigabyte GV-N250OC-1GI solution, which we have already discussed in one of our previous reviews, Gigabyte 9800 GT Silent Cell is built using “2oz Copper PCB” technology, i.e. the metal layers in the PCB are of double thickness, which improve the card’s ability to dissipate the heat from such components as GPU, memory chips or voltage regulator MOSFET. According to Gigabyte, in case all other conditions are identical this solution alone helps lower the GPU temperature by about 5-10%, which unfortunately, we can’t check, because for an experiment like that would require two absolutely identical graphics accelerators differing only by the thickness of the metal PCB layers. Nevertheless, this statement doesn’t contradict any laws of physics, so it has the right to exist.

The graphics core is powered via four-phase voltage regulator using polymer dielectric capacitors and low Rds(on) MOSFET. They used ON Semiconductor NCP5388 controller chip. External power is connected via standard six-pin PCIe 1.0 connector, which is a little hard to reach because of the long-bed heatsink of the graphics card cooling system that goes over it. The card is also equipped with GamerHUD chip that is a special feature of selected Gigabyte graphics solutions. It allows flexible control of the GPU and memory voltages using the utility with the same name.

It is a little strange to see obvious overclocking related features in a solution quipped with a passive cooling system and definitely not intended to be overclocked. Of course, Gigabyte 9800 GT Silent Cell could become a good experimental platform for overclocking if you get yourself a good cooling fan for its heatsink, but I don’t think that overclockers and enthusiasts would be the primary target group for this solution.

The card is equipped with eight Samsung K4J10324QD-HJ1A GDDR3 chips, each 1 Gbit in capacity (32Мx32) that can work at 1000 (2000) MHz frequency at 1.85 V voltage. The actual memory frequency is a little lower - 900 (1800) MHz, which is in fact a reference frequency for GeForce 9800 GT. The use of 1 Gbit chips is another unique peculiarity of Gigabyte 9800 GT Silent Cell: graphics cards like that are usually equipped with 512 MB of memory, but here we have twice as much – 1 GB. I don’t think it really matters for relatively slow graphics solutions like GeForce 9800 GT, but we still have to acknowledge it as a positive factor.

The GPU is marked as G92-283-B1, however, GPU-Z erroneously reports its revision as A2, i.e. sees it as 65 nm G92 rather than a newer 55 nm G92b. The graphics core works at official Nvidia frequencies of 600 MHz for the primary domain and 1.5 GHz for the shader processor domain. G92 features 128 unified shader processors, 112 of which are active. There are also a total of 64 texturing units with 56 active ones. In other words, one of the eight computational blocks is disabled in the core, just the way it is supposed to be in a GeForce 9800 GT.

Unfortunately, we couldn’t overclock the Gigabyte 9800 GT Silent Cell solution we had in our lab with the cooling system as is, namely in passive mode: the best we could do was gain 20-30 MHz GPU frequency, that is why we decided not to proceed at this point. In fact, there is nothing surprising here: passive cooling systems work at their full capacity right from the start that is why any overclocking attempts may rapidly overload them and cause graphics card overheating. I am sure that with additional heatsink cooling you can achieve much better results, but we are going to leave it at the mercy of true overclocking fans who are not afraid to resort to such measures as hardware modification of the voltage regulator circuitry and use of liquid nitro for cooling purposes.

The card is equipped with a not very common set of connectors: instead of two DVI-I ports there is one DVI-I, one VGA and one HDMI, which is an absolutely justified solution considering Gigabyte’s positioning of this graphics card. The mention of “golden plating” of the HDMI connector has no real practical meaning and cannot possible improve the quality of the digital signal going through it. However, many consumer electronics manufacturers have been using this marketing trick for a long time although any user with a little experience will smile at it at best. The card doesn’t support the outdated analogue video outs.

As for the cooling system, it is extremely simple in design and consists of a pretty large aluminum heatsink connected to the copper base plate with three heatpipes:

 

This whole thing is attached to the graphics card PCB with four screws, but since it is not very heavy and the graphics chip is protected with a metal contour framing, you can’t really damage the GPU. Some memory chips contact the heatsink base plate via elastic purple pads, but the other ones aren’t cooled in any particular way, which eliminates the whole point of memory cooling in general. The only possible reason for these pads to be of any practical value is to prevent the cooler base from shifting or angling.

Some of the heatsink plates are sticking out of the case through the slits in the retention bracket – Gigabyte uses this solution on all their graphics cards equipped with passive cooling systems. Theoretically, these slits can improve cooling efficiency if the air pressure inside the system case is higher, because in this case hot air from the heatsink will come out. However, Gigabyte insists on the contrary, i.e. that these slits are used to suck cool air from outside into the system case. And the schematic image on the back of the box shows this particular airflow scenario.

Overall, Gigabyte 9800 GT Silent Cell cooler is very simple, I can even say primitive. However, due to the fact that it uses a heatsink with large effective cooling surface area, it should theoretically work very well, provided that there is proper ventilation inside the system case. Our tests confirmed that Silent Cell cooler does its job well enough – under heavy load the GPU temperature remained around 74-75 °C, which is a very good result for a fully passive cooling solution. However, it is important to keep in mind that it worked inside a very spacious Chieftec LBX-01 system case and of course, we wouldn’t recommend sticking Gigabyte 9800 GT Silent Cell into a small poorly ventilated system case, just like any other graphics accelerator equipped with a fanless cooling solution, because it may cause overheating and lead to untimely death of the card.

 
Pages: [ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ]

Discussion

Comments currently: 2
Discussion started: 09/09/09 02:09:23 AM
Latest comment: 09/09/09 08:36:44 AM

View comments

Add your Comment