I found this article earlier and thought it was interesting and haven't seen it posted before.
There's been a lot of debating about 4870x2 versus a single 5870 in recent days with many people tending to focus on the benchmarks alone, whilst neglecting to mention the improvements brought to the table by 5870:
They just need to give their driver team a kick up the bum now.
There's been a lot of debating about 4870x2 versus a single 5870 in recent days with many people tending to focus on the benchmarks alone, whilst neglecting to mention the improvements brought to the table by 5870:
First off, let’s consider some of the new image quality features present in the ATI Radeon HD 5800 Series GPUs. Following the feedback we’ve received, the texture filtering quality has been improved such that we now have a near perfect circle in the anisotropic filtering tests - the same level of filtering can be achieved irrespective of the angle the texture is at as it appears into the screen. However, beyond this, all the texture weights and levels of detail are now calculated at higher precision than previous generations of AMD GPUs (i.e. the ATI RadeonTM HD 4800 series).
Game image quality improvement doesn’t stop with texture quality though. Anti-Aliasing also sees some improvements. We’ve made some architectural changes to improve the performance of our CFAA (Custom Filter Anti-Aliasing) modes and also the performance delta between 4x Multi-Sample Anti-Aliasing (MSAA) and 8x MSAA is very small, making 8x AA attainable to use in many more cases. Additionally, largely due to your feedback, Super-Sampling Anti-Aliasing makes a comeback. Although Super-Sampling is one of the oldest types of AA we did need to make hardware changes to iterate each of the subsamples over a single draw call and this, coupled with the raw performance of ATI Radeon HD 5800 series GPUs, makes for good use-case scenarios in many DirectX® 9 and OpenGL titles.
Then we come to power. There is a general industry trend towards great power efficiency, but we’ve certainly heard that echoed from many end users, especially where GDDR5 products are concerned. With the ATI Radeon HD 5800 series we’ve implemented a new memory controller that, despite higher memory speeds and data rates, is incredibly power efficient at load and idle.1 Coupled with the 40nm process and other architectural power improvements this enables a peak board power of 188W whilst providing up to twice the performance of the previous generation (i.e. the ATI Radeon HD 4800 series GPUs)1. Additionally, we now have the capability of switching the memory speed of GDDR5 devices dynamically and enter into “low strobe mode” (a mode with similar signaling as GDDR3) enabling us to crank up to 4.8Gbps bandwidth at peak operation, and down to 0.6Gbps bandwidth at idle. When taken in conjunction with a low idle engine speed of 157Mhz this enables us to get great idle power figures of 27W or below. 1 We didn’t stop there and offered something extra to those of you running multiple GPU’s per system - by making use of Windows Vista® and Windows® 7’s “Linked Adapter” mode we can determine when the additional GPUs in a multi-GPU setup are not required to be used (such as in desktop operation) and drop their idle power even lower than 27W, thus enabling you to have fantastic performance on tap when its needed but not chewing up loads of power when it’s not.
Low power operation allows us to take care of another area that registered a lot of feedback from our users of the ATI Radeon HD 4800 Series, and that is in the area of GPU heat. Although ASIC’s can typically run at very high temperatures with no issues, many users expressed their concerns on the previous generation (i.e. the ATI Radeon HD 4800 series), but on the ATI Radeon HD 5800 series we are able to run full speeds at much lower peak temperatures. What may be perceived as the obvious trade off for lower peak operating temperatures would be that this has come from fan speed and the audibility has increased, however in the case of the ATI Radeon HD 5870 graphics card, the increased board size facilitates greater surface area for heat dissipation via the fansink, so in fact we don’t need to trade off in fan speeds. Likewise, with such low idle/desktop power thanks the low idle/desktop power we can also run the fan as low as 1200RPM, much lower than we’ve run in previous generations (i.e. the ATI Radeon HD 4800 series), while the ASIC stays in approximately a 40-50C operating temperate range (in an open case). 1 The fan itself has had changes, with new bearings that produce a much lower tone, effectively making it barely audible while idling and producing a less piercing note at speed.
We’ve also put additional protection on to the board in order to better cope with runaway power scenarios. Whilst our previous boards have been able to capture unusual thermal events in a graceful manner, runaway power scenarios resulted in the board protecting itself by shutting down. With the ATI Radeon HD 5800 series we’ve implemented a hardware-level overvolt protection scheme where a signal from the regulators can be fed into the GPU directly and the GPU can take action if the regulators indicate they are operating out of their specification. In the unlikely event that such a scenario happens, rather than the board turning off, the GPU is designed to clock down to get the regulators back into a normal operating zone and then clock back up when they have done so.
Finally, we wanted to give a little something else back to you, in the form of a new look and feel for the product. We set out to make a new fansink design that would make the board seem more of an all encompassed product, rather than merely another PC component, but still unmistakably say “ATI Radeon” (quite literally as it turns out!). Whilst the PCI Express specification would tend to dictate a fairly rectangular box, we sought to give these boards some more visual cues and styling’s, and we hope that you’ll like the result - judging by some of the images and avatars already cropping up, it appears to have already captured some people’s imaginations, and we’re getting a kick out of seeing them.
They just need to give their driver team a kick up the bum now.
