AMD Phenom II X4 (Deneb) 940 Launch, Review & Overclocking - PAGE 1

Introducing the Phenom II 940

Deneb is finally here.

The original 65nm Phenom took its sweet time to market, and frankly, underwhelmed us compared to Intel's Penryn.

The TLB bug did not help.

AMD must have pulled out all the stops in bringing the "K10.5" aka Deneb as quickly as possible, but it was still later than everyone (except Intel) would have liked.

The Phenom II 940 - and the Phenom II 920 - are the first two 45nm Deneb processors that are being released by AMD - and AMD is finally hitting the clock speeds it was originally intending for the 65nm parts, with the Phenom II 920 coming in at 2.8GHz and the Phenom II 940 running at 3.0GHz.

Ok, so what's different between the Phenom X4 and the Phenom II?

• Geometry shrink to 45nm (from 65nm)
• L3 shared cache increased to 6MB (from 2MB)
• L3 cache 2 cycles faster than on previous Phenom
• increased DRAM bandwidth
• cores flush L1+L2 caches to L3 on halt to save power
• path based indirect branch prediction
• double the bandwidth for in-core probing
• larger load/store and floating point buffering
• reduced missed buffer lifetime
• improved LOCK pipelining
• floating point register-to-register MOV improvements

What does all of the above boil down to?

• faster, larger L3 cache
• more memory bandwidth
• slightly faster core

Now for the technical specifications:

• AMD Phenom II X4 920: 2.8GHz (14x200) multiplier-locked
• AMD Phenom II X4 940 BE: 3.0GHz (15x200) multiplier-unlocked
• 45nm DSL SOI (silicon on insulator) technology
• approx. 758M transistors
• approx. 258mm2 die size
• max case temp of 62'C
• L1 cache: 64KB code + 64KB data per core (512KB total)
• L2 cache: 512KB unified code/data per core (2MB total)
• L3 cache: 6MB shared unified code/data cache
• dual 64-bit memory channels can be ganged to 128 bits
• Memory Controller: Supports up to DDR2-1066 and DDR3-1800 up to 17.1GB/sec
• one HT3.0 link, 1.8GHz 16 bit in / 16 bit out, up to 14.4GB/sec
• 940 pin grid array
• Vcore between 0.875-1.5V
• Max 125W TDP
• made in Fab 36, Dresden, Germany

Now was that not a lovely bit of techno-bable?

What all of this boils down to is AMD hoping that the Phenom II X4 will be able to compete with Penryn-class 45nm processors from Intel, and not be too far behind the lower end of the Core i7 lineup.

With this in mind, I decided to benchmark the Phenom II X4 940 against:

• Phenom X4 9950 Black Edition at stock 2.6GHz - the previously fastest stock AMD processor
• Phenom X4 9950 Black Edition overclocked to 3.0GHz - the same speed as the Phenom II 940 - let's see if the improvements have helped!
• Intel QX9650 Extreme Edition (same speed as Q9650) - same 3GHz clock rate, at twice the price, however my old test results used a different video card
• Intel QX9770 Extreme Edition - MUCH more expensive, runs at 3.2GHz, with same video card
• Intel Core i7 920 - just for fun, same video card, more expensive platform

I wanted to see where the Phenom II X4 940 would sit :-)