Memory upgrade I want to insatll in my asus p4b266 that actually have an Infineon DDR 256Mb, 133MHz memory another extra chipset of a DDR 256Mb, 333MHz chipset.

Yes you can upgrade to any DDR that is rated at PC2700/PC2100/PC1600 and non ECC. Up to 2 gigabytes.

SDRAM (Synchronous DRAM)
Almost all systems used to ship with 3.3 volt, 168-pin SDRAM DIMMs. SDRAM is not an extension of older EDO DRAM but a new type of DRAM altogether. SDRAM started out running at 66 MHz, while older fast page mode DRAM and EDO max out at 50 MHz. SDRAM is able to scale to 133 MHz (PC133) officially, and unofficially up to 180MHz or higher. As processors get faster, new generations of memory such as DDR and RDRAM are required to get proper performance.


DDR (Double Data Rate SDRAM)
DDR basically doubles the rate of data transfer of standard SDRAM by transferring data on the up and down tick of a clock cycle. DDR memory operating at 333MHz actually operates at 166MHz * 2 (aka PC333 / PC2700) or 133MHz*2 (PC266 / PC2100). DDR is a 2.5 volt technology that uses 184 pins in its DIMMs. It is incompatible with SDRAM physically, but uses a similar parallel bus, making it easier to implement than RDRAM, which is a different technology.

Manufacturer Specifications - EPoX EP-4BDA533I Number of Slots:
Slot 1
Slot 2
Each memory slot can hold DDR PC2700,DDR PC3200 with a maximum of 1GB per slot.*
*Not to exceed manufacturer supported memory.

• 184-pin DIMM Banking: 2 (2 banks of 1)
• Chipset: Intel 845D
• Error Detection Support: ECC and non-ECC
• Graphics Support: AGP 4X
• Max Component Density: 512Mb
• Max Unbuffered DDR SDRAM: 2048MB
• Module Types Supported: Unbuffered only
• Supported DRAM Types: DDR SDRAM only
• USB Support: 1.x Compliant

Q: What memory goes into my computer, and will a faster speed be backward-compatible?
A: DDR memory with support for DDR PC2700,DDR PC3200 speeds.
Because DDR memory is backward-compatible, you can safely upgrade your system with any of the guaranteed-compatible DDR speeds listed below, even if your manual calls for PC1600 or PC2100 speeds.
Q: How much memory can my computer handle?
A: 2048MB.
Adding the maximum amount of memory will improve performance and help extend the useful life of your system as you run increasingly demanding software applications in the future.
Q: Do I have to install matching pairs?
A: No.
No, you can install modules one at a time, and you can mix different densities of modules in your computer. But if your computer supports dual-channel memory configurations, you should install in identical pairs (preferably in kits) for optimal performance.
Q: Does my computer support dual-channel memory?
A: No.
Your system does not support dual channel.
Q: Does my computer support ECC memory?
A: Yes.
Your system supports ECC. You can put non-ECC modules into an ECC system, but be sure not to mix ECC and non-ECC modules within a system. Install the same type of modules that are already in your system.

Care to read this link;

http://www.simpletech.com/upgrades/asus/a7v266mx/a7v266mxamdathlonxp/

Hope it answers your questions.

Simply, yes you can. just open the case and put in the new boards. you can buy higher spec. memory(as long as the pins are the same number)
I.E. ddr-sdram boards will fit and as long as the speed is the same (132.8 Mhz) or higher.
I changed from 133Mhz to 333Mhz and the performance was much improved.
The PC3200 is the important bit, should be the same.
after you change the memory ,try running disc clean up in "start, all programs, accessories, disc clean up" this will also speed things up as well as de-fragmennting your drive(s)

G-Skill is what I put in all my custom built computers.  Search newegg.com and you will find what youare looking for.  You want PC2700 DDR.

From Asus tech: Memory 3 184-pin DIMM slots for PC1600/PC2100 DDR SDRAM
Supports up to 2GB memory
No ECC supportThis is only compatible RAM so make sure your new chip is PC1600 or PC2100. If you mis the 2 it the faster RAM will run at the slower chip speed. Hope this helps.

K8V SE Deluxe DDR400 Memory Qualified Vender List
The following table lists the memory modules that have been tested
and qualified for use with this motherboard.
Size Module Vendor Model Chip Brand
SS/
DS
Chip
256M Micron MT8VDDT3264AG-40BC4 Micron SS MT46V32M8TG-5BC
512M Micron MT16VDDT6464AG-40BC4 Micron DS MT46V32M8TG-5BC
128M Infineon HYS64D16301GU-5-B Infineon SS HYB25D256160BT-5B
256M Infineon HYS64D32300GU-5-B Infineon SS HY25D256160BT-5B
512M Infineon HYS64D32300GU-5-B Infineon DS HY25D256800BT-5B
256M Infineon HYS64D3230HU-5-C Infineon SS HYB25D256800CE-5
512M Infineon HYS64D6320HU-5-C Infineon DS HYB25D256800CE-5
512M Samsung M368L6432ETM-CCC Samsung DS K4H560838E-TCCC
256M ATP AG32L64T8SQC4S Samsung SS K4H560838D-TCC4
256M Brain Power B6U808-256M-SAM-400 Samsung SS K4H560838D-TCC4
512M Brain Power B6U808-512M-SAM-400 Samsung DS K4H560838D-TCC4
512M Apacer 77.10736.464 Samsung DS K4H560838D-TCC4
256M ADATA MDOSS6F3G31YK1EZZ Samsung SS K4H560838D-TCC4
128M NANYA NT128D64SH4B1G-5T NANYA SS NT5DS16M16BT-5T
512M NANYA N512D64S8HB1G-5T NANYA DS NT5DS32M8BT-5T
256M Hynix HYMD232646B8J-D43 AA Hynix SS HY5DU56822BT-D43
256M Kingston KVR400X64C3A/256 Hynix SS HY5DV56822BT-D43
512M Kingston KVR400X64C3A/512 Hynix DS HY5DV56822BT-D43
512M Winbond W9451GCDB-5 Winbond DS W942508CH-5
256M Kingston KVR400X64C25/256 Winbond SS W942508BH-5
256M ADATA MDOWBFF3G31JB1EAE Winbond SS W942508BH-5
512M TwinMOS M2G9J16AGATT9F081AA4T TwinMOS DS TMD7608F8E50D
256M TwinMOS M2S9I08AFAPS9F0811A-T PSC SS A2S56D30ATP
256M KINGMAX MPXB62D-38KT3R KINGMAX SS KDL388P4EA-50
512M KINGMAX MPXC22D-38KT3R KINGMAX DS KDL388P4EA-50A
256M CORSAIR CMX256A-4000 XMS4000V1.1 CORSAIR SS
ive found the best prices at tigerdirect.com and they ship it right to your door. make sure the tiger ppl have the exact match and dont replace your order with more expensive replacements as some of these substitutions require voltages that your motherboard CAN NOT produce and will not work.. you also want to make sure to buy low density ram, it performs better, is a few bucks more than high density, but worth EVERY penny. E-bay is notorious for selling cheap high density ram on thier site.
If you stick to the list above, you shouldnt have any issues.
This should fixya up! please rate...

i can find no spec on this but,if your notebook can take upt 576MB of memory, i would expect 2 x 256MB to be the max, as installing 1 x 512MB would be doubling the capacity allowed by one module slot.