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PCB Design and Specifications

The card doesn’t seem to differ from the 65nm version of GeForce GTX 260/GTX 260 Core 216 but EVGA tried to make it original by putting a sticker on the cooler’s casing and painting the side of the casing red.

The card is 27 centimeters long and won’t suit compact system cases. This is a drawback because the opposing Radeon HD 4870 is only 23 centimeters long.

There are in fact more differences than you can see at first sight. We did not expect Nvidia to develop a new PCB design for the 55nm version of GeForce GTX 260 Core 216. It wouldn’t make sense because the card is in fact a cut-down version of GeForce GTX 280. However, Nvidia did develop it. We can see a lot of differences as soon as we remove the cooler.

First of all, the memory chips are now all located on the face side of the PCB and there are 14 of them. That is, this PCB design provides for a 448-bit memory bus without the opportunity of enlarging it to 512 bits. We don’t know the reason for Nvidia to develop the new PCB. Perhaps the company wanted to cut the manufacturing cost but we don’t think they win a lot with the new design. The updated PCB still looks very complex and expensive.


Old Geforce GTX 260 PCB


New Geforce GTX 260 PCB

The power section has been revised considerably. The old version used a five-phase regulator that represented a cut-down variant of the seven-phase regulator of the GeForce GTX 280, but the 55nm GeForce GTX 260 has four phases in the GPU voltage regulator and there are different power transistors in them. The bad news for the owners of liquid cooling systems or nonstandard air coolers: monolithic cooling solutions developed for the 65nm GeForce GTX 200 series and designed to cool not only the GPU and memory chips but also the power circuit elements will not fit the 55nm cards because their power elements are located differently.

The voltage regulator is based on a four-phase PWM controller NCP5388 located on the reverse side of the PCB. Next to it, there is a tiny mysterious chip marked as BR=AL U07. It must be responsible for controlling the dedicated two-phase memory voltage regulator. The card has two external power connectors. Both are of the 6-pin PCIe 1.0 variety and have a load capacity of 75W. The metallic frame around the GPU is one more difference whereas the left part of the PCB, with the interface connectors and the NVIO chip, has been left intact.

The EVGA card uses GDDR3 chips from Samsung. Marked as K4J52324QH-HJ1A, the chips have a rated frequency of 1000 (2000) MHz and a voltage of 1.9V.

There are 14 of them here, offering an 896MB memory bank with a 448-bit memory bus. According to the official specifications from Nvidia, the GeForce GTX 260 has a memory frequency of 1000 (2000) MHz irrespective of the GPU version. This provides a memory bandwidth of 112GBps. But EVGA pre-overclocked the memory chips to 1053 (2106) MHz, increasing the bandwidth to 117.9GBps. This is somewhat higher than the Radeon HD 4870’s memory bandwidth of 115.2GBps but leaves no room for further overclocking considering the rated frequency of the chips. We’ll check out the card’s overclockability in the appropriate section of the review, though.

We could not check visually how smaller the G200b was. Like the old version of the chip, the new version is equipped with a metallic heat-spreading cap. We did not dare remove that cap as we needed the card for our tests. Anyway, the numbers speak for themselves: the new G200 is as large as 470 sq. mm as opposed to the old version’s 576 sq. mm (the RV770 is far more compact, measuring 260 sq. mm only, but also much simpler in terms of transistors). The GPU is marked as G200-103-B2, so you can easily tell it from the old version that used to be marked as G200-100-A2.

According to the official specs, the GeForce GTX 260 Core 216 has 576MHz and 1242MHz frequencies for the main and shader domains, respectively, but the GPU of the EVGA card is pre-overclocked to 625MHz and 1350MHz. That’s not much, and we can’t say if the frequency potential of the G200b is higher than that of the G200. We have seen 65nm versions of GeForce GTX 260 Core 216 pre-overclocked to higher frequencies, so we will try to overclock the EVGA card further shortly.

The GPU configuration is standard for GeForce GTX 260 Core 216: 216 shader processors, 72 texture processors, and 28 raster back-ends. If the card has good overclockability, it can deliver the performance of the GeForce GTX 280 and more.

The card is equipped with two dual-link DVI-I ports (with support for resolutions up to 2560x1600 inclusive), a universal analog video output, two SLI connectors (for building a graphics subsystem out of two or three such cards), and a two-pin S/PDIF connector (to translate an external S/PDIF audio stream into HDMI using the included cable).

 
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