# Presentation: 153146

## Processor Technology

- John Gordon, Peter Oliver
- e-Science Centre, RAL
- October  2002

- All details correct at time of writing 09/10/02

## Outline

**What is a CPU?**
**Current Technologies**
**CPU, memory and Motherboads**
**Concentrate on x86 architectures**
**INTEL**
**AMD**
**Longer view**
**Parallel CPUs**
**Overview of Other vendors**
**SGI, SUN, COMPAQ, HP, IBM**

## What is a CPU? (1)

**A CPU is comprised of**
**Clock to 3GHz**
**The controls how often an instruction can be performed**
**Integer Units 1 to N**
**Used to perform integer maths**
**Floating point Units 1 to N**
**32/64bit arithmetic**
**Memory Cache L1, L2 and L3**
**Instruction and data Caches**
**L1 Typically 8-64k **
**L2 128-512k**
**L3 as large as 8MB**
**Memory Bus**
**Speed **
**bus speed 100Mhz or higher**
**Width**
**What is transferred per cycle**
**Typically 64bit**

## What is a CPU? (2)

**Memory Architecture**
**SDRAM**
**One fetch per bus cycle**
**DDR**
**Two fetches per bus Cycle**
**RDRAM**
**Special Units**
**SSE single precision (32 bits ) SIMD units**
**SSE2 Double precision (64 bits) SIMD units**
**SIMD – single instruction multiple data**
**Eg A(1:100)=A(1:100)*.08**
**Ie multiply each array element by 0.08.**

## Brief History

## Differences between Intel and AMD

| CPU | Integer | FP | Cache
 | Special |
| --- | --- | --- | --- | --- |
| PIII | 3 | 1 | L1 16I/16D
L2 512k | SSE |
| Athlon | 3 | 2 + store | L1 64I/64D
L2 256k | SSE (3DNOW!) |
| Opteron | 3 | 2 + store | L1 64I/64D
L2 ~1-2MB? | SSE,SSE2
64bit |
| PIV | 2 | 1 | L1 12I/8D
L2 512k | SSE,SSE2 |
| Itanium 2 | 4 | 4 | L1 16I/16D
L2 256k
L3 3MB | EPIC IA-64 |

## Current Technologies - Intel (1)

**Intel Offerings Celeron and PIII**
**SSE , single precision SIMD units**
**BLAS libraries very fast (using ATLAS **_[http://www.netlib.org/atlas/](http://www.netlib.org/atlas/)_** )**
**700Mflops DGEMM (70% of peak) for 1GHz PIII (256k L2)**
**PIII dropped**
**Celeron moved to PIV core as of 1.7GHz**
**See **_[http://www.specbench.org](http://www.specbench.org/)_** for latest numbers**

## Current Technologies - Intel (2)

**Intel Offerings PIV, Xeon, Itanium (IA64)**
**PIV**
**BLAS libraries very fast (using ATLAS)**
**SSEII - double precision SIMD**
**2.8Gflops for 2.2GHz P4 (using SSEII)**
**Xeon**
**PIV core with SMT (symmetric multithreading)**
**Itanium 2**
**EPIC**
**3.5 Gflops DGEMM  for 1000MHz Itanium 2**
**Price of itanium prohibitively expensive**

## Current Technologies - AMD (1)

**AMD Offerings Duron, AthlonXP and AthlonMP**
**Duron, (phased out?) AthlonXP for single CPU**
**AthlonMP required for Dual SMP**
**SSE , single precision SIMD units**
**BLAS libraries very fast (using ATLAS)**
**2.4 Glops DGEMM (75% of peak) 1.6GHz AthlonMP**

## Current Technologies - Motherboards

**PIII, PIV and AthlonMP available in Dual form**
**Both Xeons and AlthonMP cost more**
**a 1.8GHz AthlonMP costs ~1.5x 1.8GHz AthlonXP **
** ****a 2.4GHz Xeon costs ~1.5x  2.4GHz PIV**
**A 2.4GHz Xeon costs 1.3x 1.8GHz AthlonXP**
**64bit/66MHz PCI for both**
**Motherboard costs**
**AthlonMP Tyan S2462UVM  (SCSI, PCI, 100Mbit)**
**~x2 Xeon supermicro P4DP6 (SCSI, PCI-X,100Mbit) **
**1U rack mount routine**
**Blades becoming available for even higher density**
**PCI-X 64bit/133MHz**
**Very interesting for high speed interconnects**
**Myrinet (www.myri.com), Wulfkit (www.wulfkit.com), Quadrics (www.quadrics.com)**
**PIV Quad motherboards**
**Expensive**
**Limited memory bandwidth - bus based**

## CPUs on the horizon Intel (1)

**Very difficult predicting the future ******
**Intel.**
**Celeron**
**1.7GHz , 1.9GHz, 2GHz (128 L2) Q3 and Q4 (P4 core)**
**single CPU only ?**
**PIII**
**1.4GHz probably the last CPU?**
**PIV/Xeon**
**3.06 GHz (512k L2) 533MHz bus (4*133) November 2002**
**3.2 GHz (512k L2) 533MHz bus (4*133) Q1-2 2003**
**XeonMP –highend**
**256k L2, 1MB L3 1.6GHz –2GHz systems with 4 or more procs.**
**PIV Prescott – crystal ball gazing **
**3.2GHz, 4.0GHz , 1MB L2 , 666 MHz bus Q3 2003, Q4 2003**

## CPUs on the horizon Intel (2)

**IA-64 **
**Compiler choice critical**
**32bit x86 code  supported but how fast?**
**McKinley Itanium 2**
**1GHz 1.5MB-3MB L3 cache**
**400MHz bus (cf itanium 266MHz)**
**very expensive 10 time the cost of PIV?**
**Madison**
**1.2/1.6 GHz > 3MB L3 cache 2H 2003**

## CPUs on the horizon AMD (1)

**AMD**
**Duron silently dropped?**
**AMD AthlonXP and MP lines**
**2800 333MHz FSB, 256k L2 cache **
**3000 and beyond 333MHz FSB, 512k L2 cache “Barton” H1 2003**

## CPUs on the horizon AMD(2)

**AMD HAMMER Series 4th Q 2002 1st 2003**
**64bit x86 CPU with 32bit x86 native**
**SSE and SSEII SIMD units**
**AMD - 8000 Chipset (Hyper transport)**
**PCI - X (133MHz)**

## Parallel CPUs (1)

**Parallel high end CPUs**
**Itanium 2**
**DMH (DDR memory Hub)**
**Good memory bandwidth **
**(6.4GB/s)**
**Poor scalability, all shared!**
** **

## Parallel CPUs (2)

**Parallel high end CPUs**
**Hammer/Opteron**
**5.4GB/s memory bandwidth**
**Non shared therefore scales well**
**Ideal for memory intensive calcs**
**Cc-numa problems for Linux?**

- 2 way

- 4 way

## Motherboard Trends

- Previously we chose dual cpus
- Only low-end cpus not supported (Celeron, Duron)
- Boards not much dearer
- Vague feeling that PP work would saturate NIC and/or Bus >2 cpus
- In future
- Only top-end cpus supported (eg Xeon)
- Boards dearer
- Need to monitor whether increased costs are still offset by increased density

## Other vendors

**There are still other vendors in the market place**
**SGI, SUN, COMPAQ, HP, IBM**
**SGI**
**R14k 600MHz , Specint 483, Specfp 499**
**Not very fast but large scale cc-numa SMP systems 1024 procs**
**Moving to IA-64**
**SUN**
**Ultra sparc III (1050MHz, Specint 537, Specfp 701**
**Speed OK but medium sized SMP systems**
**COMPAQ/HP**
**Alphaserver systems - EV68 1.25GHz , Specint 928, specfp 1327**
**fast cpu and systems 1 - 32 cpu SMP**
**Moving to IA-64 with HP**
**HP**
**750MHz PA-8600, Specint 569, Specfp 526**
**Heavily involved with IA-64**
**1GHz Itaniumn 2 Specint 807, specfp 1356**
**IBM**
**Power4 Specint 804, Specfp 1202**

## Summary

- Don’t just judge on clock speed. A long way from RISC
- Can we consider AMD for general-purpose user batch?
- Keep re-costing the optimal number of cpus/box.
- Keep watching blades.
- Everything will be different tomorrow!

## References

**In no particular order**
**www.ugeek.com**
**www.amd.com**
**www.intel.com**
**www.aceshardware.com**
**www.amdzone.com**
**www.jc-news.com**
**www.theregister.co.uk**
**www.theinquirer.net**
**www.top500.org**
**www.theinquirer.net**