These two GPUs are very similar. However, one is less in price than the other. It seems the only difference between them is the Effective Memory Clock. My question is, is the better effective memory clock worth the extra money?
XFX HD-587X-ZNFC Radeon HD 5870 1GB 256-bit DDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150476
VS
XFX HD-587X-ZNFV Radeon HD 5870 (Cypress XT) 1GB 256-bit DDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150490
XFX HD-587X-ZNFC Radeon HD 5870 1GB 256-bit DDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150476
VS
XFX HD-587X-ZNFV Radeon HD 5870 (Cypress XT) 1GB 256-bit DDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150490