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PCB Design and Specifications

The graphics card uses the PCB design and cooler of the reference GeForce GTX 470 we described in our earlier review. Quite a reasonable solution if our supposition of the temporary status of the GeForce GTX 465 is true. Compare for yourself:

 

 

The single visible difference is the stickers of the manufacturing firms. The Gigabyte card looks more impressive, even flashy. The Zotac GeForce GTX 465 has standard dimensions and will easily fit into nearly any modern system cases. Even if the case is not too long and the card nearly touches the HDD rack, this won’t be a problem because its power connectors are located at the top of the PCB rather than at its butt-end as on the Radeon HD 5850.

 

It is easier to see the difference with the coolers removed. There is actually only one discrepancy: the GeForce GTX 465 has eight memory chips plus two empty seats for them whereas the GeForce GTX 470 has 10 memory chips. Another small difference we can see is that the Zotac card features screened DVI connectors.

The power subsystem of the GeForce GTX 465 is the same as that of the GeForce GTX 470 and follows a 4+1-phase design. The number of phases and the number of power transistors per phase in the GPU voltage regulator has not changed. There are four phases managed by an NCP5388 controller from ON Semiconductor.

There are also no changes in the memory voltage regulator which is managed by an Anpec Electronics APW7165 controller. There are two external power connectors, both of the 6-pin variety. This is enough even for the GeForce GTX 470 and should suffice for the GeForce GTX 465 which is expected to need less power (the real situation is somewhat different, however, as you will see shortly).

K4G10325FE-HC05 memory from Samsung is installed on the card. Considering the low clock rate, cheaper chips with higher access time might be used, but Nvidia does not try to save on them for some reason. Each memory chip has a capacity of 1 Gb (32 Mb x 32), so eight such chips make up a memory bank of 1 gigabyte accessed across a 256-bit memory bus. The memory frequency is only 802 (3208) MHz which is a ridiculously low level for modern GDDR5 memory. The resulting memory bandwidth is rather low at 102.7 GBps – far lower than that of the GeForce GTX 275 and Radeon HD 5850. This is the consequence of the low memory clock rate chosen by Nvidia for the GeForce GTX 465. A more complex PCB wiring for a 320-bit memory bus wouldn’t have helped to reach higher frequencies, though. The card lowers its memory frequency to 67 (270) MHz in power-saving mode as all GeForce GTX 400 series products do.

The GPU looks interesting. Besides its ordinary marking, the GPU of our Zotac GeForce GTX 465 has the text “Qual Sample”. So, although we’ve got the card in its retail packaging, it must have participated in the qualification tests of the new GeForce GTX 400 series model. The pink sticker on the reverse side of the PCB suggests the same as it reads “Not for Resale”. The GPU is the same revision as the samples installed on the senior models of the series. The middle number in the marking is different, as usual. It is low here: 030. This sample of the GF100 chip was produced in late March and must have been found defective. But later it was found suitable for the GeForce GTX 465. The GPU clock rates meet the official specifications which coincide with the GeForce GTX 470 specs: 608 and 1215 MHz for the main and computing domains, respectively. These frequencies are dropped to 51/101 MHz in 2D applications to save power. For simple tasks that require some GPU resources there is a medium mode with frequencies of 405/810 MHz. As for the GPU configuration, the GeForce GTX 465 has 352 unified shader processors, 44 TMUs and 32 RBEs.

By the way, there are rumors on the Web that the GeForce GTX 465 can be easily transformed into a GeForce GTX 470 by simply loading the BIOS code from the senior model into it. We doubt this because the new card has a 256-bit memory bus whereas the GeForce GTX 470 has a 320-bit bus. Even if Nvidia has not blocked the very opportunity to modify the card in such a way, the BIOS image has to be changed for that. Our attempt to load unmodified BIOS from our GeForce GTX 470 into the GeForce GTX 465 was a failure. The system would start up and show a black screen. Fortunately, we could quickly restore the card’s original BIOS and went on with our tests.

Using the same PCB as the GeForce GTX 470, the Zotac has the same interfaces as well: two DVI-I ports, one mini-HDMI, and two MIO connectors. The card supports 3-way SLI configuration but building a graphics subsystem out of three GeForce GTX 465 can hardly make much sense. If you want to use more than two monitors simultaneously, you must have a SLI configuration with at least two such graphics cards. The GeForce GTX 465 can deliver audio over HDMI but does not support Protected Audio Path, which makes it less interesting for HTPC users.

The cooling system has been borrowed from the GeForce GTX 470, too. It consists of a not-very-large heatsink pierced with five heat pipes that contact with the GPU’s heat-spreading cap. A thick layer of dark-gray thermal grease ensures proper thermal contact (but there were even more of it on our GeForce GTX 470). The elastic pads that take the heat away from the memory chips and power circuit components are dark-gray rather than green here, but we don’t think their color affects their performance. This cooler did not do very well on the GeForce GTX 470 despite the direct touch technology. Let’s see how it performs on the GeForce GTX 465.

 
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