the card was actual a 128mb version. In answer to my own question i installed the card and ran my own benchmark using 3Dmark2001se here is the results.
(original) GeForce2 MX400 64MB Scored:2852
(new) GeForce3 Ti200 128MB Scored: 5693
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i was shocked what a huge difference considering on ebay the GeForce3 Ti200 128MB sells at only 10pound more than the GeForce2 MX400 64MB what a huge amount of improved performance for 10pound
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thanks any way for all your help
mark