205

Sapphire HD 4870 X2 2048 MB Review

Name: Sapphire HD 4870 X2 2048 MB
Brand: Sapphire

W1zzard

on Aug 11th, 2008,

in Graphics Cards.

Manufacturer: Sapphire

(205 Comments) »

Introduction

Today is the launch of the long anticipated AMD Radeon HD 4870 X2. This card features two RV770 graphics processors on a single PCB. The RV770 has been used on the HD 4850 and HD 4870 in the past. Another product announced today is the Radeon HD 4850 X2. The HD 4870 X2 uses GDDR5 memory, while the 4850 variant uses GDDR3. Compared to the single GPU designs, both X2 cards feature twice the available video memory per GPU. The HD 4870 X2 has 2 GB of GDDR5 - 1 GB per GPU. AMD is positioning their HD 4870 X2 as "the fastest graphics card on the planet" - which is reflected in the price of $549.
Sapphire's HD 4870 X2 follows the AMD reference design specifications to the letter, the only difference is the Sapphire sticker on the cooler.

One novel feature of the HD 4870 X2 is that it has an additional direct-GPU-to-GPU interconnect called CrossFire Sideport (XSP). The XSP offers an additional 5 GB/s interlink bandwidth between the GPUs but is not enabled at this time. Yes, you read correctly. The official reason why the XSP is disabled at this time is because that much bandwidth is not required with current applications and it will be enabled at some point in the future via driver update.
One major advantage of the XSP that I see is that transfers between the GPUs would have a lower latency. The Gen2 PCI-E bridge will certainly be fast, but it will take a short time to process the incoming data and send it out to the other GPU (<140 ns). With the XSP's point-to-point interlink this delay is eliminated. So my speculation is that AMD is working on using the XSP feature but the driver support simply doesn't work as intended at this time.

	Radeon HD 3850	Radeon HD 3870	GeForce 9600 GT	GeForce 8800 GT	GeForce 9800 GT	Radeon HD 4850	GeForce 9800 GTX	GeForce 9800 GTX+	GeForce 8800 GTX	GeForce GTX 260	Radeon HD 4870	Radeon HD 4850 X2	GeForce GTX 280	Radeon HD 4870 X2
Shader units	320	320	64	112	112	800	128	128	128	192	800	2x 800	240	2x 800
ROPs	16	16	16	16	16	16	16	16	24	28	16	2x 16	32	2x 16
GPU	RV670	RV670	G94	G92	G92	RV770	G92	G92	G80	GT200	RV770	2x RV770	GT200	2x RV770
Transistors	666M	666M	505M	754M	754M	956M	754M	754M	681M	1400M	956M	2x 956M	1400M	2x 956M
Memory Size	256 MB	512 MB	512 MB	512 MB	512 MB	512 MB	512 MB	512 MB	768 MB	896 MB	512 MB	2x 1024 MB	1024 MB	2x 1024 MB
Memory Bus Width	256 bit	256 bit	256 bit	256 bit	256 bit	256 bit	256 bit	256 bit	384 bit	448 bit	256 bit	2x 256 bit	512 bit	2x 256 bit
Core Clock	670 MHz	777 MHz	650 MHz	600 MHz	600 MHz	625 MHz	675 MHz	738 MHz	575 MHz	576 MHz	750 MHz	625 MHz	602 MHz	750 MHz
Memory Clock	828 MHz	1126 MHz	900 MHz	900 MHz	900 MHz	993 MHz	1100 MHz	1100 MHz	900 MHz	999 MHz	900 MHz	1000 MHz	1107 MHz	900 MHz
Price	$99	$125	$90	$140	$160	$170	$185	$200	$295	$270	$280	$400	$430	$550

Packaging & Contents

Sapphire's beautiful package is full of statements like "Dual VPU Power", "Prepare to Dominate", "Dual Core Pixel Processing Power", "Watch the latest Bly-Ray [sic] and HD movies". A listing of the actual clock rates is nowhere to be found.

You will receive:

Graphics card
Manual + Driver CD + 3DMark Vantage full version + PowerDVD
DVI Adapter + HDMI Adapter + S-Video Adapter
TV out cable
2x CrossFire bridge (why two?)

The Card

The Sapphire HD 4870 X2 uses the long form factor (~ 30 cm), that we know from the HD 3870 X2. A large metal plate covers the memory chips on the back. As expected the card uses a dual slot cooler to be able to keep the two GPUs cool.

The card has two DVI ports, basically the most common output configuration these days. In case you need an analog VGA port you can use the included DVI adapter. When using an HDMI adapter (also included), you will also have access to HDMI+HDCP+Audio, which allows easy setup of a media PC. All recent ATI Radeon cards have a Realtek HD Audio device integrated inside the GPU silicon. This means that you don't have to connect any additional cabling to the graphics card for HDMI Audio. A new feature of the HD 4xxx Series is support for 7.1 HDMI audio, the older HD 3xxx cards supported only 5.1.

Here are the front and the back of the card, high-res versions are also available (front, back). If you choose to use these images for voltmods etc, please include a link back to this site or let us post your article.

A Closer Look

AMD's reference design cooler is powerful, big and heavy. The total weight of the card is 1060 grams (GTX 280: 920g, HD 4870 790g). Please make sure you properly screw down any large VGA card before moving your case to a LAN party.
As you can see there are two copper blocks making contact with the GPUs, while the memory chips and other circuitry is cooled with thermal pads. The memory chips on the back of the card are cooled by a metal plate (yes it's metal, even though it feels like plastic).

Two of these cards (or 4870 X2 + 1x/2x 4870) can be combined into a CrossFireX rig with even more graphics power.

Just like on the HD 3870 X2, the power connectors are angled downward which helps in smaller cases. Please note that you need to connect both 6-pin and 8-pin PCI-E power connectors for the card to run. Two 6-pins won't work; you must use an 8-pin power connector for the 8-pin plug.

Mmmm, nice. These are the first GDDR5 memory chips from Hynix that I see. On the HD 4870, chips from Qimonda are used. The model number of the chips on the HD 4870 X2 is H5GQ1H24MJR T0C, they are specced for up to 4.0 Gbps (= 1000 MHz real clock). In total you will find 16 of these memory chips on the 4870 X2, eight per GPU.

The PLX Technology PEX 8647 is a PCIe Gen2, 5.0GT/s 48-lane, 3-port PCIe Switch (marketing spec sheet here).
While the bridge chip on the HD 3870 X2 supported only PCI-E 1.1 transfers, this one has full support for PCI-E 2.0, and also offers new features like Dual Cast and Read Pacing (see the spec sheet for explanations).