The rumors have been around for weeks: Today AMD's Radeon HD 4890 is officially introduced and Nvidia counters with the Geforce GTX 275. PC Games Hardware reviewed both cards.
Ati Radeon HD 4890 vs. Nvidia Geforce GTX 275 [Source: view picture gallery]
Today AMD's Radeon HD 4890 and Nvidia's Geforce GTX 275 are officially launched. As the names indicate the two cards are not aiming for the absolute high-end performance but at a little lower level. The motto is "Evolution not Revolution” - actually both chips are old fellows.
Just some words regarding the topic of Non Disclosure Agreement: All reviews and tests published before today have not been approved by AMD or Nvidia and aren't up-to-date. We tested until the last possible moment to deliver benchmarks results of all graphics cards with the latest drivers. Furthermore we directly compare the two newcomers and don't publish two separate tests. Ati Radeon HD 4890
Ati Radeon HD 4890: Two 6-Pin power connectors [Source: view picture gallery]
The Radeon HD 4890 is the designated successor of the HD 4870 and now AMD's fastest single GPU graphics card. This isn't reached with fundamental changes but with increased clock speeds. AMD's graphics department Ati did some fine tuning and delivered a chip with a higher frequency range, codename RV790. For now the RV790 is used on the HD 4890 only and is clocked to 850 MHz. Compared to the HD 4870 (750 MHz) this equals a theoretical performance advantage of 13 percent. So this is used to full extend, the memory frequency was also increased by 150 MHz: The HD 4890 is working with 1,950 instead of 1,800 MHz (+8 percent) ex factory. AMD places the card at about 210 US-Dollar and thus in between the HD 4870 and the dual GPU HD 4870 X2.
Furthermore the RV790 has some detail improvements compared to the RV770. An AMD document
mentions the support of Burst Memory Reads for example, but an AMD employee recently told us that this in particular is an error in the document.
Nvidia Geforce GTX 275
Burst Memory Reads: Not included in the RV790 [Source: view picture gallery]
Nvidia Geforce GTX 275: Two 6-Pin power connectors [Source: view picture gallery]
The Geforce GTX 275 is Nvidia's answer to the Radeon HD 4890. The card is based on the board of the GTX 260-216 (55nm). On this PCB sits a full-fledged GT200b with 240 ALUs and 80 TMUs, but it can only use a 448 Bit interface and 896 MiByte VRAM. Thus the GTX 275 is a hybrid of the GTX 285 and GTX 260 qualities - or the put it another way: It is a "halved” GTX 295 with slightly increased clock speeds. Those are 633/1,404/1,134 MHz (GPU/ALU/VRAM). So the GTX 275 has a higher calculating power than the GTX 280, but a lower bandwidth and less video memory. According to Nvidia the recommended retail price is 239 Euros - definitely intended as a competition to AMD's Radeon HD 4890.