PCB Design and Specifications

The Sapphire HD 4670 Ultimate Edition is the same size as the reference Radeon HD 4670 GDDR3 but that’s where the similarity ends. It uses a different PCB that differs from the reference PCB in everything including the color of the solder mask. Blue is quite a standard color for Sapphire’s products, though.

The PCB is rather simple because of the 128-bit memory bus and the lack of external power connection. The GPU and memory voltage regulators are simple, too. The former has a 2-phase design with two power transistors in each phase and the option of adding one more transistor into each phase using the empty seats on the reverse side of the PCB. An unknown chip marked as BN-AK DOU serves as a PWM controller.

A simple single-phase regulator controlled by a NeXsem NX2114 chip is responsible for the memory chips.

The peak power consumption of a reference Radeon HD 4670 is not higher than 50 watts, so there is no need for an additional power connector. The card’s power requirements are satisfied by the power section of the PCI Express x16 slot.

There are eight GDDR3 chips on the PCB – four on each side of it. The chips are marked as Hynix H5RS5223CFR-N0C. According to the manufacturer, this means a capacity of 512 Mb (16 Mb x 32). The N0C suffix says that the chips have an increased voltage (2.05 V) and a rated frequency of 1000 (2000) MHz. The total amount of local graphics memory is 512 megabytes, which is standard even for today’s inexpensive graphics cards.

The memory frequency of the HD 4670 Ultimate Edition is reduced to 873 (1746) MHz, suggesting that Sapphire does not position this product as a gaming solution. The reduction of operating frequencies is always good for a card with passive cooling. The downside is that, considering the 128-bit bus, the card’s memory bandwidth is only 27.9 GBps, which may have a negative effect on its performance in games. However, the card’s memory could work at 1000 (2000) MHz when overclocked, and we used such overclocking in order to emulate a reference Radeon HD 4670.

The RV730 processor installed on this card was manufactured on the 49th week of 2008, in early December. Its memory controller is set up for working with GDDR3. The core frequency is 750 MHz, like that of the reference card. The GPU has a standard configuration with 64 unified superscalar processors (5 ALUs in each), 32 texture processors, and 8 RBEs. As opposed to the RV770, there is no metallic frame on the die package and the die itself is placed at an angle of 45 degrees. Overclocking was unrewarding: the GPU failed to work at 770 MHz, being only stable at 764 MHz. We did not benchmark the card at the overclocked frequencies.

The Sapphire HD 4670 Ultimate Edition has a dedicated D-Sub port although this feature is rather useless nowadays (a monitor with D-Sub interface can be connected via an adapter). Two DVI-I ports would be more appropriate for dual-monitor configurations. This graphics card seems to be targeted at the HTPC market, so the dedicated HDMI port is an advantage.

Although this graphics card has no CrossFire connectors, it can work in multi-GPU mode, exchanging data via the PCI Express bus (of course, this worsens the performance of such a tandem somewhat). To build such a tandem you need a second such card and a mainboard with a PCI Express controller that supports peer-to-peer data transfer mode. In other words, you will not be able to pair a Sapphire HD 4670 Ultimate Edition with an ordinary Radeon HD 4670 that has CrossFireX connectors. The multi-GPU mode will not be available on mainboards based on Intel’s P35 and P965 chipsets which do not support peer-to-peer mode for PCI Express devices. This is hardly a serious drawback, though. The Sapphire HD 4670 Ultimate Edition is not positioned as a gaming card anyway.