Featured Articles

Analysts expect ARM to do well next year

Analysts expect ARM to do well next year

British chip designer ARM could cash in on the mobile industry's rush to transition to 64-bit operating systems and hardware.

More...
Huawei and Xiaomi outpace Lenovo, LG in smartphone market

Huawei and Xiaomi outpace Lenovo, LG in smartphone market

Samsung has lost smartphone market share, ending the quarter on a low note and Xiaomi appears to be the big winner.

More...
Intel Broadwell 15W coming to CES

Intel Broadwell 15W coming to CES

It looks like Intel will be showing off its 14nm processors, codenames Broadwell, in a couple of weeks at CES 2015.

More...
Gainward GTX 980 Phantom reviewed

Gainward GTX 980 Phantom reviewed

Today we’ll be taking a closer look at the recently introduced Gainward GTX 980 4GB with the company’s trademark Phantom cooler.

More...
Zotac ZBOX Sphere OI520 barebones vs Sphere Plus review

Zotac ZBOX Sphere OI520 barebones vs Sphere Plus review

Zotac has been in the nettop and mini-PC space for more than four years now and it has managed to carve…

More...
Frontpage Slideshow | Copyright © 2006-2010 orks, a business unit of Nuevvo Webware Ltd.
Thursday, 05 January 2012 08:46

AMD confirms Radeon HD 7970 only has 32 CUs

Written by Jon Worrel

radeon logo_new

Denies allegations of inactive core logic

In the final week of 2011, the graphics hardware community was abuzz with an interesting rumor that AMD may have been concealing some truth behind the architectural capabilities of its recently [paper]-launched Radeon HD 7970 GPU (officially launching January 9, 2012).


radeon hd_7970_front 

The rumor, stemmed from a few leaked Sapphire documents, claimed that AMD’s high-end 28nm Tahiti GPU may have been a deviation from an older specification, and that the Radeon HD 7970 model actually launched with 2048 stream processors (SPs) distributed across 40 graphics compute units (CUs) instead of being distributed across 32 graphics compute units. The documents implicated that AMD had been hiding eight inactive CUs in its core logic, regardless of the fact that AMD never revealed any images of its Southern Islands GCN architecture on silicon in order to determine if this was true. 

Nevertheless, AMD, Nvidia and even Intel have been recognized in the past for creating redundant architectural components on production silicon wafers in an effort to increase chip yields. The process, commonly known as “harvesting,” ensures that the full architectural specification of particular GPU and CPU models is guaranteed across the chip if one section fails to perform. For example, the infamous Nvidia Geforce GTX 480 was a GPU that featured 512 CUDA cores available on the GF100, yet only 480 of them were actively available and the remaining 32 were disabled to achieve higher yields.

amd 28nm_tahiti_architecture 

AMD 28nm Graphics Core Next (GCN) architecture, complete with 32 CUs
 

According to a recent report from our friends at Bright Side of News, AMD has denied any allegations of the Radeon HD 7970 containing more graphics compute units (CUs) than contained in the 28nm Tahiti GPU specification.

Bright Side of News:
"We contacted AMD's representatives such as Mr. Chris Hook and Eric Demers and received a straight answer from the company, represented by Mr. Hook, Senior PR exec:

"There are no hidden cores…'"

All in all, we can be assured that the Radeon HD 7970 has 2048 stream processors distributed across 32 CUs. AMD is dealing with 4.3 billion transistors on this incredibly dense 28nm GPU, and it is illogical to claim that the company’s engineers would harvest an additional hundred million or so transistors on die that would essentially “sit there” and do nothing.

Last modified on Thursday, 05 January 2012 11:45

Jon Worrel

E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
blog comments powered by Disqus

 

Facebook activity

Latest Commented Articles

Recent Comments