http://tinyurl.com/6gaflpr - this psychometrics blog has a factor analysis on data from the WISC IV that shows a g factor that is indeed most strongly weighted on verbal ability.

http://tinyurl.com/ywls5h - describes performance on the WISC IV with a section on ethnic groups

"The WISC IV normative sample is based on 2,200 children from 11 age groups (each one year wide), with an equal number of males and females in each group, and an ethnic breakup that matches the March 2000 US Census data very closely. There were 5 levels of parental education, and 4 geographical areas covering the whole United States and Hawaii. Sattler classifies the sampling method as "excellent." Of note, there were only 1,100 in the norming sample for Arithmetic....

Asian-American children scored 3 points higher than Euro-American children...
PRI and PSI are 5 points higher than VCI and WMI for Asian-American children...

Something to keep in mind:
VCI accounts for 62% of variance in g
PRI accounts of 45% of variance in g
WMI accounts for 43% of variance in g
PSI accounts for 23% of variance in g"

It looks to me like the areas with the strongest advantage for Asians aren't strongly related to g or to information (under verbal VCI above) or arithmetic (under working memory WMI), so I would be surprised if they had a much higher g, rather than an elevated processing speed and perceptual reasoning ability. Which advantages look a lot like "Hanzi advantages" actually. It might be that the exam culture Frost describes was pretty much "consumed" by the difficulty of the characters, so selection was not on general intelligence as such so much as on mastering an exceedingly complex writing system.

http://tinyurl.com/dhaweh - describes the four different facets of the test (in more detail).

On the other hand, Asians apparently have the most pronounced advantage on the Raven's Matrices, which is supposedly very g-loaded (there are various numbers bandied around on the internet). Although that seems surprising to me as the (also non-verbal reasoning) PRI section in the WISC (where Asian advantage apparently comes from) is not very g-loaded at all (the matrix reasoning subtest on the WISC which is modelled on the Raven's Matrices has a relatively high loading, but not stellar).