Introduction

The train of new graphics cards keeps rumbling by with another stop at the AMD headquarters.  On September 23rd we saw the release of the AMD Evergreen-based graphics card, the Radeon HD 5870, that was followed up exactly a week later by the Radeon HD 5850 that offered the same feature set with slightly lower performance and a slightly lower price.  

AMD is impressing us again with yet another new graphics release pulling the Evergreen architecture even lower in price.   This new GPU was known as Juniper and is physically a new die spin, not simply a Cyprus core with some additional cores disabled.  The new Radeon HD 5770 and Radeon HD 5750 that we are reviewing today again breath new life into both AMD and the PC gaming market.

The New Radeon HD 5770 and HD 5750

First, let me say that we aren't going into the gory details of the Evergreen GPU architecture in this review - if you have yet to read up on it or need a refresher, please head over to our Radeon HD 5870 review where we go into some good detail on what has changed in the move from the 4000-series to the new 5000-series including DX11 support, improved computing power and of course the popular Eyefinity technology. 

Today's release brings the total count of DX11-ready, 40nm Evergreen GPUs up to four and is really solidifying AMD's lead and dominance in next-generation graphics technology.  As you would expect, the HD 5770 and HD 5750 are lower priced, lower performing parts and take over where the Radeon HD 4850 left off.

As I mentioned, the Juniper-based GPUs are a completely new GPU spin based on the Evergreen design.  Here is a diagram of this new GPU:

Juniper comes with 10 SIMD engines comprised of a total of 800 stream processors - half the number of the HD 5800-series but equal to the number of shaders found in the HD 4800-series of graphics cards.  The texture unit count has also been cut in half to 40 as has the memory controller interface: 128-bit GDDR5 with up to 76.8 GB/s of bandwidth.  Z/stencil ROP units are cut to 64 (from 128 in Cyprus) and color ROPs are cut to 16 - we are pretty much looking at half the total features and theoretical performance.

Both Juniper GPUs consist of 1.04 billion transistors; less than half the count of the Radeon HD 5800s. 

As we go over in detail in our HD 5870 review, there are some new features that make the HD 5000-series of GPUs stand out from the 4000-series:

• Support for DirectX 11 and Shader Model 5.0
• Support for OpenCL 1.0 (and likely OpenCL 1.1)
• Angle independent anisotropic filtering (finally!)
• "Nearly free" 4xMSAA
  
• Very low idle power consumption
• AMD Eyefinity multi-monitor gaming - first performance testing here
  
• Three monitor support on a single card

The first of two new graphics card we are going to be looking at today, the Radeon HD 5770 has 800 stream processors running at 850 MHz delivering up to 1.36 TFLOPs of raw compute power.  Idle power consumption sees another drop here as well, down to 18w from 27w, and maximum board board is very reasonable.  It includes 1GB of memory running at 1200 MHz. 

The second offering is the Radeon HD 5750 that disables on SIMD engine for a total of 720 stream processors at 700 MHz; it is likely not by chance that the raw compute power on this card breaks the 1 TFLOPs barrier.  The HD 5750 will be offered in either a 512MB or 1GB solution (at 1150 MHz), but we are hoping 1GB becomes the norm.

For those interested, here is the raw numbers break down:

At less than half the transistors on the same 40nm technology, it makes sense that the Juniper chip is going to be significantly smaller than Cyprus.

Radeon HD 5870 - Cyprus core

Radeon HD 5770 - Juniper core